Skip to main content

Full text of "Appleton's dictionary of machines, mechanics, engine-work, and engineering : illustrated with four thousand engravings on wood ; in two volumes"

See other formats


-«►>•• >>ai 



ao " 








:» ' 















, ^2>3»~sjS' 

' 5~> 






3 I? 5» 





^ddoscsji* '. 


> > 

2» >2fe^_ 

+ i^ ~- 




_ »3R> "TJCS 2fcL 

3s> :rx>x> 



.Z>5> — 

ZXS2» 3g^« 





>3~^ : vx>^i3>-a>> 

zae>j>>Z>^ 5 Jt>^ — 


3»l> :> ■■>■ r>' »,»:>;> 


i^" - 

"3»".3>-£>-" . 










_-?-<-> ^m 


> ^^* 

t-*>^->. • 

>^ — > ?iIX» >-3»Jg> :^30 

t>> Z» )£X» '13?3»> '^>^> 

■■ >• "5 _ > y>^> 

- „*y»>>> i> 330 ^ 
so>>>»- x» ^a>^> ra 

:^»» iza» ".'». J»* ->» -"?-=^ -33^^ 

• ;■ i~S& ^> z>" ~^*> ■>> a ^^ ^St -^ 

£G> Z> /3*Z>: 


/ 5 

"2- 1>*t> 

Digitized by the Internet Archive 

in 2011 with funding from 

The Institute of Museum and Library Services through an Indiana State Library LSTA Grant 







VOL. I. 



549 & 551 BROADWAY. 

IroL I 

Entered, according to Act of Congress, in the year 1850, by 


In the Clerk's Office of the District Court of the United States for the Southern 

District of New York. 

Entered, according to Act of Congress, in the year ISfiS, by 


In the Clerk's Office of the District Court of the United States for the Southern 

District of New York. 







In presenting to the public a new edition of the " Dictionary of 
Mechanics, Machines, Engine "Work, and Engineering," the publishers 
have thought it necessary that the whole work should be revised ; 
that those novelties which were presented in the original work, and 
have not stood the test of use, should be struck out ; those processes 
which have been superseded, should give place to those at present 
employed ; and that those new machines which have not as yet 
been fully tested by time, but bid fair to be of practical value, as 
well as older machines previously omitted, should be added. 

They are aware that in the first work many errors both in com- 
mission and in omission crept in — errors in judgment, and errors in 
arrangement — that though in general standard authors were drawn 
from, yet credit was often not given to the authority in the article 
itself. Time, experience, and consultation with persons of practical 
minds, have helped to correct errors in judgment. As to the arrange- 
ment, many articles were introduced into the original edition under 
their least characteristic heads ; references were not full, often wrong. 
This has been remedied : the captions of articles have been changed, 
references have been made fuller and more accurate, and we trust 
that the knowledge contained in this work may be much more 

With reference to the citation of authorities, the publishers are 
aware that in such a work as this, being but a compilation of ab- 
stracts, without in every case the full carrying out of the reasoning 
ab initio, the- value of the results depends on the author ; in the 


same way, when the results of experiments are given, it is of the ut- 
most importance that the name of the experimenter should be given. 
Readers prefer to exercise their own judgment in this matter to the 
ipse dixit of any editor or editors that could be brought to the 
compilation of this work. In this view, authorities have been sup- 
plied to the older articles as far as possible, and invariably to the 

"With the above prunings, the supplying of omissions, and the 
introduction ">f much new matter, to a work con taming as much 
really valuable material as any of its class, the publishers offer the 
present edition with confidence, as worthy of the appreciation of 
the public. 


Encyclopaedias and Dictionaries of Art have now become so popular, and their ad- 
vantages so thoroughly tested, that it is entirely unnecessary to usher in the present work 
by dwelling on the peculiar merits of such publications. Every such work marks the era, 
or defines the position of the sciences treated, at its time of publication ; and, in the lapse 
of years, is record of a step by which such sciences have advanced, affording material for 
history rather than practical working examples. On this account the older encyclopae- 
dias have become almost useless to the practical man of the present day ; but the later 
the works, the greater their value — provided they are, as they should be, latest records of 
the progress of science. 

No work like the one now offered to the public has ever originated here ; and of the 
foreign works republished, none occupy the same ground, or exhibit, in the slightest de- 
gree, the state of mechanical arts in this country. The Dictionary is intended to be 
a Dictionary of Machines, Mechanics, Engine-work and Engineering ; to present con- 
cisely and compendiously the details of valuable machines in actual use, the laws of 
matter and their application, the construction and proportion of parts of engines and 
mill-work, together with the most successful and useful examples in engineering. 

In the progress of nations, it has always been remarked that the more liberal the gov- 
ernment, the more rapid are the strides and the greater the advance in mechanical and 
industrial pursuits, and nowhere in history can a more brilliant illustration of this be 
found than in the progress of our own country ; rich in natural resources, under a free 
and beneficent government, industry is encouraged and protected, yet comparatively 
sparsely populated, the country cannot, to the fullest extent, develop its resources or 
compete with the overstocked and poorly paid population of the older countries, unless 
machines are brought to supply the place of manual labor. Without encroaching on the 
grounds of Free Trade or Protection, it is evident that, to stand on fair ground with 
our competitors, we must understand the machines and processes employed by them, 
that these machines must be adapted or improved by us if possible, or new ones invented 
better to suit our resources and develop them. 

To show, therefore, the advance of the mechanical arts both here and abroad, 10 de- 
fine their exact position at the present time as far as possible, but more particularly in 
regard to machinery, to make, as it were, a " World Industrial Exhibition" of useful ma- 
chines, and a record of their application, is the object of the present work. For this 
purpose the editors have drawn from the publications of all countries distinguished in 
mechanical pursuits. Care has been taken, in selection, to admit only such as are con- 
sidered standard and practical. In many cases, credit has been given for these selections 
at the end of the articles ; annexed also, a list of the books is given, from which selections 
were made. But credit is to be given especially to the Glasgow Engineer's and Machin- 
ist's Assistant, Boukne on the Steam-Engine, Holtzapffel's Turning and Mechanical 
Manipulation, Allgemeine Maschinen Encyclopadie, from which very able articles have 
been drawn. 

But whilst we have drawn largely from foreign works, we have not been unmindful 
of our own progress in mechanism and engineering. Many patentees of valuable ma- 
chines have kindly afforded us drawings and descriptions, among whom we would name 


E. B. Bigelow, Esq., Henry Burden, Wm. Mason, G. H. Corliss, John J. Howe, 
and many others. Very many drawings and specifications hare been taken from the 
Patent Office, and descriptions will be found in this work of machines which cannot be 
seen in operation ; as, from a mistaken consideration of the patentees, they are not open 
to inspection of visitors. We are also under obligations to Wm. A. Burke, of the Lowell 
Machine Shop, Caleb M. Marvel, of the Essex Machine Shop, and Wm. Ellis, of the 
Washington Navy Yard, for drawings and descriptions of machines. 

In the Engine department, we are under obligations to Mr. Copeland for the draw- 
ings and descriptions of the steamer Pacific. In Engineering, we owe much to the 
liberality of William J. McAlpine, in furnishing us with the description of the Dry 
Dock at Brooklyn, and the machinery used in its construction, together with the experi- 
ments made on the strength of the gates. The article Gold has been furnished by a 
distinguished metallurgist. The article on Metallurgy is by F. Overman, whose work 
on Iron stands deservedly high. The original communications have been numerous and 
valuable, and the publishers have spared neither labor nor expense to make the work 
what it should be. 

The illustrations have all been engraved expressly for the work, as large as the page 
would admit, and sufficiently distinct and in detail to answer for working drawings. 

The work is intended more directly for the practical and working man, and for those 
interested in industrial pursuits ; but to all classes it will be found important and instruc- 
tive. It will show how far the world has progressed in mechanical science — the science 
of automatic labor, the science which is destined to raise our country to the most elevated 
position in the world, to ennoble the mechanic and artisan, and to extend and diffuse 

Among the works from which materials have been selected may be mentioned the 
following : 

Annales des Ponts et Chaussees. Bibliotheque des Arts Industriels : (Masson, Paris.) Civil En- 
gineer and Architect's Journal : (London.) Engineer and Machinist's Assistant : (Blackie, Glasgow.) 
Publication Industrielle : (Armengaud Aine, Paris.) Jamieson's Mechanics of Fluids. Treatise oc 
Mechanics : (Poisson.) Allgemeine BauzeituDg mit Abbildungen : (Forster, Wien.) Organ f iir die 
Fortschritte des Eisenfcabnwesens in technischer Beziehung : (Von Waldegg, Wiesbaden.) Glasgow 
Practical Mechanic. Silliman's Journal. Allgemeine Masehinen-Eneyclopiidie — Hiilsse : (Leipzig.) 
Cotton Manufacture of Great Britain and America contrasted. Holtzapffel's Turning and Mechanical 
Manipulation. The Steam-Engine : (J. Bourne.) Eisenbahn-Zeitung : (Stuttgart.) Tredgold on the 
Steam-Engine. Dictionnaire des Arts et Manufactures : (Laboulaye, Paris.) Origin and Progress of 
Steam Navigation : (Woodcroft.) Essai sur l'lndustrie des Matieres Textiles : (Michel Alcan, Paris.) 
Griers' Mechanic's Pocket Dictionary. Templeton's Millwrights and Engineers Pocket Companion. 
Marine Steam-Engine : (Brown.) VTeisbach's Mechanics and Engineering. Barlow on Strength of 
Materials. Hann's Mechanics. Mechanical Principles of Engineering and Architecture : (Mosely.) 
Journal of the Franklin Institute. The Transactions of the Institute of Civil Engineers : (London.) 
The Artisan. Quarterly Papers on Engineering : (Published by Weale, London.) Imperial Dictionary 
— Blackie: (Glasgow.) Professional Papers of tie Corps of Boy al Engineers. Student's Guide to the 
Locomotive-Engine. Railway Engine and Carriage- Wheels : (Barlow, London.) Recueil des Machines 
Instrumens et Appareils : (Le Blanc, Paris.) Buchanan on Mill- Work. Practical Examples of Modern 
Tools and Machines: (G. Bennie.) Repertoire de l'lndustrie Franchise et Etrangere: (L. Mathias, 
Paris.) Treatise on the Manufacture of Gas : (Cleg, London.) Hodge on the Steam-Engine. Scien- 
tific American. Railroad Journal : (Sew York.) American Artisan. Mechanics' Magazine : (London.) 
Nicholson's (Peter) Dictionary of Architecture. Dictionnaire de Marine a Voiles et a Vapeur : (De 
Bonnefoux, Paris.) Conway and Menai Tubular Bridges : (Fairbairn.) Brees' Railway Practice. Bar- 
low's Mathematical Dictionary. Bowditch's Navigation. Gregory's Mathematics for Practical Men. 
Engineers' and Mechanics' Encyclopaedia : (Luke Herbert.) Patent Journal : (London.) Brees' Glos 
sary of Engineering. Encyclopaedia of Civil Engineering : (Cresy.) Craddock's Lectures on the Steam- 
Engine. Assistant Engineer's Railway Guide : (HaskolL) Mechanical Princioia : (Leonard.) Weale's 
Mathematical Tables. 




AAM. A measure of liquids among the Dutch, equal 288 pints. 

ABACUS. An instrument employed by the ancients for facilitating calculations ; similar to that now 
frequently employed for teaching children the rudiments of arithmetic, and which is commonly sold in 
our stationers' shops. It usually consists of twelve parallel wires, fixed in a light rectangular frame ; 
»ach wire carrying 12 beads or balls. There are thus 12 times 12, answering to the common multipli- 
cation table, all the results of which it demonstrates to the dullest capacity. All the operations of ad- 
dition or subtraction are likewise performed by it, by merely moving the beads from one side to the 
other of the frame. By thus smoothing the difficulties of acquiring arithmetical knowledge at the very 
outset, and rendering it quite obvious and amusing at the same time, the apparatus becomes one of 
considerable importance in educatioa 

Another kind of Abacus consists of a series of parallel wires fixed in a frame like the former. On 
sach wire there are nine little balls ; the lowest stand for units, the next above for tens, the next hun- 


Hundreds of Thousands 

Tens of Thousands 





ireds, and so on up to any number. The frame is divided into two compartments, a and A, by a cross 
wire at c, which is sufficiently raised above the wires to allow the little balls to slide under it. Suppose 
the whole 63 balls to be placed in the compartment a, and it be proposed to note the sum of 4,346,072 
it is effected by sliding the balls shown in b from their previous situation in a. 

ABACUS. The plate or shallow block forming the uppermost member of a capital, so called for 
the sake of distinction, for when a similar one is placed beneath the base of a column, it is called a 

ABELE. See Woods, varieties of. 

ABUTMENT is a term commonly applied by engineers to those fixed parts of mechanism used to 
resist a thrust. In the case of Bridges the term is applied to the land pier, whether subject to thrust 
or not. 

ACACIA. See Woods, varieties of. 

ACCELERATION is the increase of velocity in a moving body, caused by the continued action of 
the motive force. When bodies in motion pass through equal spaces in equal times, or, in other words , 
when the velocity of the body is the same during the period that the body is in motion, it is termed 
uniform motion, of which we have a familiar instance in the motion of the hands of a clock over the 
face of it ; but a more correct illustration is the revolution of the earth on its axis. In the case of a 
oody moving through unequal spaces in equal times, or with a varying velocity, if the velocity increase 
with tlie duration of the motion, it is termed accelerated motion ; but if it decrease with the duration o f 
the motion, it is termed retarded motion. A stone thrown up in the air, affords an illustration of both 
these cases, the motion during the ascent being retarded by the force of gravity, and accelerated by the 
same during the descent of the stone. All bodies have a tendency to preserve their state, either of rest 
or of motion ; so that if a body were set in motion, and the moving force were withdrawn, the body, if 
unopposed by any force, would continue to move with the same velocity it had acquired at the instant 
the lnoyiog force was withdrawn. And if a bodv in motion be acted upon by a constant force, (as the 



force of gravity,) the motion becomes accelerated, the velocity increasing as the times, and the whole 
spaces passed through increasing as the square of the times ; whilst the proportional spaces passed 
through during equal portions of time, will be as the odd numbers, 1, S, 5, 7, <fce. ; and the space passed 
over in any portion of time will be equal to half the velocity acquired at the end of such time : which 
results will be better brought to view in the following Table : 




lor each Time. 

T^'al Space 




1 = 1 2 




3 4. 1 = 4 = 2» 




5 + 3 + 1 = = 3 3 




7 + 5 + 3 + 1 =16 

It has been ascertained by experiment, that a body falling freely by its own weight from a state ol 
rest, will descend through 16 feet 1 inch in the first second of time, and will have acquired a velocity 
of 32 \ feet; but from the rapidity with which the velocity increases, we cannot extend the experiment, 
for in only four seconds a body falling freely would pass through a space of 256 feet. But by an 
ingenious contrivance of Mr. Atwood, the laws of motion above laid down may be verified experiment- 
ally. The machine is called " Atwood's machine," after the name of the inventor ; and the principle 
of its action consists in counteracting a portion of the gravitating power of a body, by the gravitating 
power of a smaller body ; so that the absolute velocity, and the spaces passed through, sliall be less 
than in the. case of bodies descending freely, whilst, as the force is constant, the same ratio of progres- 
sion will hold in both cases. The annexed figure represents one of these machines . a a a is a triangulai 
frame upon three moveable legs; 6, a small platform suspended from it by a universal joint cc, and 
supporting two upright standards dd, in which the axis of a light brass wheel e revolves with very little 
friction. Over a groove in the periphery of the wheel passes a very light and pliable silk thread, from 
the ends of which hang two equal weights/, g. Into the under side of b is screwed a square rod h, 
descending to the floor, to which it is secured in a perpendicular position by small pins passing through 
holes in the claws at ii. On the face of the rod is a scale of inches ; k is a 
brass guide, fixed at the upper part of the rod h, so that when the top of the 
weight g touches the lower side of k, the under side of g is on a level with 
the top, or commencement of the scale ; I is a small stage, moveable along 
the rod !>, and having a hole in it sufficiently large for the weight g to pass : 
on one side is a tightening screw m: n is another moveable stage, fitted with 
a tightening screw o, as also a fork p, turning upon a hinge. The experi- 
ments are conducted as follows : — A small circular weight is placed upon g, 
which is pulled up to the top of the scale, and the stage n is screwed to the 
rod A, on a level with the lower part of the weight /, which is held down 
upon it by the fork p. Upon releasing f from the fork, the weight g descends 
with a slow, but gradually accelerated motion, and the number of inches the 
weight has descended, at each successive beat of a pendulum, (suspended 
from another triangle,) is observed upon the scale ; and if the additional 
weight be such as to cause g to descend through three inches in the first 
second, then it will cause it to descend through one foot in two seconds, and 
through 6 \ feet in five seconds. If the additional weight be removed, and a 
small bar of equal weight, but of a length exceeding the diameter of the 
hole in /, be placed upon g, and the stage I be set at any division of the 
scale, at which the weight would arrive at the end of any number of seconds, 
the stage will intercept the bar in its descent, and the weight will continue 
to descend with the velocity it had acquired upon reaching I. Thus, if the 
velocity at the end of the second second be two feet, in which case the 
weight would have descended one foot in that time, if the stage be set at one 
foot upon the scale, it will intercept the bar at the end of the second second, 
and the weight g will move with a uniform velocity of two feet per second, 
through the remaining portion of its descent. If it is required to illustrate 
the case of retarded motion, the small circular weight is placed upon the 
weight g, and a similar small weight upon the weight/, so that g, still out- 
weighing /, will descend ; but as soon as the stage / intercepts the bar with 
the small weight upon it, / becomes the heaviest, and g will descend with a 
velocity decreasing as the squares of the times, counted from the time of g 
passing the stage I. 

ACIDS. Sour substances, or in chemistry such as neutralize the alkalis and other salifiable bases. 

AERIAL PERSPECTIVE, is that which presents objects diminished in size and weakened in tint, 
in proportion to their distance from the eye : but the term relates principally to the color. 

AFFINITY, a term used in chemistry to denote that kind of attraction by which the particles of 
different bodies unite, and form a compound possessing properties distinct from any of the substances 
which compose it, Thus, when an acid and alkali combine, a new substance is formed, called a salt, 
perfectly different in its chemical properties from either an acid or an alkali ; and the tendency which 
these have to unite, is said to he in consequence of affinity. 

AFRICAN BLACKWOOD. See Woods, varieties of. 

AIR. "Pure air consists almost entirely of nitrogen and oxygen gases, with a very small portion 
»f carbonic acid gas. Of 100 parts of air, reckoning by weight, 75.55 parts are nitrogen, 23.32 oxy- 
gen, and 1.13 carbonic acid and watery vapor. Both as respects weight and bulk, nitrogen forms 
the chief ingredient of the atmosphere. 

The weight or pressure of the atmosphere is eaual to the w-eisrbt of a column o* water 34 feet in 



height, or to a column of mercury 30 inches in height, or 14.7 lbs. per square inch at a mean tem- 
perature. But air and all kinds of gases are rendered lighter by the application of heat, for then 
the particles of the mass are repelled from each other or rarefied, and occupy a greater space. 
Rarefied air, being specifically lightest, mounts above that of common density ; hence, change of 
temperature is the principal cause of winds. If air be very suddenly compressed into a small com- 
pass, the heat given out is so considerable as to be sufficient to ignite inflammable substances. This 
property has been turned to advantage in an apparatus denominated, "An Instantaneous Light Ma- 
chine," which consists of a piston accurately fitted and worked in a cylinder, by the sudden stroke 
of which the volume of air contained in the cylinder becomes so much compressed as to give 
out sufficient heat to set fire to a piece of the substance termed German tinder. 

For the necessity of air in respiration and combustion, see Warming and Ventilation. 

AIR CHAMBER, See Pumping Engines. 

AIR ESCAPE, a simple and ingenious contrivance for letting off the air from water-pipes. If a 
range of water-pipes be led over a rising ground, it will he found that air will collect in the higher 
parts and obstruct the progress of the water ; to remedy which inconvenience the Air Escape is em- 
ployed. A hollow vessel is attached to the upper part of the pipe, in the top of which vessel there is 
fixed a ball cock, adjusted in such a way, that when any air collects in the pipe, it will ascend into the 
vessel, and by displacing the water, cause the hall to descend, and thus open the cock, when the air is 
allowed to escape. No water, however, can escape, for when that fluid rises in the vessel above a cer- 
tain height, the ball rises and shuts the cock ; new air then collects, displaces the water, lowers the ball, 
the cock is opened, and it again escapes. 

AIR-GUN. A machine in which highly-compressed air is substituted for gunpowder to expel the 
ball, which will be projected forward with greater or less velocity, according to the state of conden- 
sation, and the weight of the body projected. 

It consists of a lock, stock, barrel, ramrod, &c, of about the size and weight of a common fowling- 
piece. Under the lock at b is screwed a hollow copper ball c, perfectly air-tight. This ball is fully 
charged with condensed air, by means of the syringe B, previous to ife ceing applied to the tube at b. 
Being charged and screwed on as above stated, if a bullet be rammed down in the ban-el, and the 
trigger a be pulled, the pin in b will, by the spring-work in the lock, forcibly strike out into the balL 
and thence by pushing it suddenly, a valve within it will let out a portion of the condensed air, which, 
rushing through the aperture in the lock, will act forcibly against the ball, impelling it to the distance 
of 60 or 70 yards, or farther if the 
air be strongly compressed. At 
every discharge only a portion of 
the air escapes from the ball; 
therefore, by re-cocking the piece 
another discharge may be made, 
which may be repeated for a num- 
ber of times proportioned to the 
size of the ball. The air in the 
copper ball is condensed by the 
syringe B in the following manner. 
The ball is screwed quite close on 
the top of the syringe ; at the end 
of the steel-pointed rod a is a stout 
ring, through which passes the rod 
k ; upon this rod the feet should be 
firmly set ; then the hands are to 
be applied to the two handles i i 
fixed on the side of the barrel of the 
syringe, when, by moving the bar- 
rel B steadily up and clown on the 
rod a, the ball c will become charged with condensed air, and the progress of condensation may be esti- 
mated by the increasing difficulty in forcing down the syringe. At the end of the rod k is usually a square 
hole, that the rod may serve as a key for attaching the ball to either the gun or syringe. In the inside 
of the ball is fixed a valve and spring, which gives way to the admission of the air, but upon its emission, 
comes close up to the orifice, shutting out the external air. The piston-rod works air-tight by a collar 
of leather on it, in the barrel B ; it is therefore obvious, that when the barrel is drawn up, the air will 
rush in at the hole h ; when it is pushed down, it will have no other way to pass from the pressure of 
the piston but into the ball c at the top. The barrel being drawn up, "the operation is repeated, until 
the condensation is so great as to resist the action of the piston. 

AIR-VALVE, a valve commonly applied to steam-boilers for the purpose of preventing the forma- 
tion of a vacuum when the steam happens to be condensed within the boiler. The mode of action of 
these valves is very simple. A valve in the top of the boiler opening inwards, is kept shut by a coun- 
terweight at the end of a lever ; but whenever the steam in the boiler happens to be condensed, a 
vacuum is formed, and the air-valve is opened by the pressure of the atmosphere, consequently the air 
enters and destroys the vacuum. The interior of the boiler being allowed to remain in the state of 
vacuum, the atmospheric pressure from without might cause its sides to collapse, and thus effect the 
destruction of the boiler. 

AIR-PUMP. An apparatus to extract or exhaust the air from a vessel, to produce a vacuum. 

Fig. 5 is a sectional view of the common form of the Air-pump. R is a bell-shaped glass ves- 
sel, open only at the bottom, and whose rim is ground perfectly flat, so that it may rest on every 
point, on a brass plate S S. which is likewise ground to a flat surface, so that when a little hog's-lard i? 



rubbed upon the edge of the glass vessel, commonly called the receiver, and then the rim placed, by t 
kind of circular sliding motion, upon the brass plate, no ah- can pass in or out of the receiver, between 
its edge and the plate. Through the centre of the brass plate there is drilled an orifice A, from which 
orifice there is led a pipe AB, forming a communication between the receiver R and the interior of the 
cylinder BPV, which communication may be opened or closed by means of a stop-cock at G. The 
cylinder or barrel BPV is furnished with a piston BP accurately fitted to the cylinder, but capable ol 
free motion up and down, which motion is effected by means of a piston-rod DC, which moves through 
a stuffed or air-tight collar at D. The bottom of the cylinder or ban-el is furnished with a valve V 
opening outwards. This cylinder communicates with another BXPV, constructed and furnished in 
similar manner ; and the two piston-rods are provided with 
racks C at the top, the teeth of which are acted upon by those 
of a a-aeel placed between them, as may be seen in the figure. 
Let us now attend to the mode of action. Suppose the stop- 
cock at G open, and the pistons as they are in the figure. The 
piston BP being at the top, a free communication is formed 
between the receiver R and the first cylinder, and the piston 
being pushed down past the orifice at B, the air contained in 
the cylinder or barrel will be forced into less space or com- 
pressed, and of course its elastic force increased. In conse- 
quence of this increased elasticity, the valve at V will be open- 
ed, and the ah expelled. When the piston is lifted, this valve 
will be shut by the pressure of the atmospheric air without 
thus a portion of the air which was contained in the receiver, 
communication pipe, and barrel, has been erpelled, and that 
which remains will consequently be less dense ; another stroke 
of the piston will diminish the density still more ; and this pro- 
cess may be continued until the density be so diminished, that 
when compressed by the descent of the piston to the bottom of 
the barrel, its elastic force is only sufficient to open the valve 
V. It will be easily seen, that the exhaustion of the air in the 
receiver depends on the elasticity of the air; for when the pis- 
ton descends and expels the air contained within the barrel, which it will do completely, if it go to the 
bottom, and then in returning, the valve V being shut, a vacuum will be formed in the barrel until the 
piston in its ascent passes the orifice B, when the air within the receiver will expand and fill the whole 
cavity. The operation of the second barrel and piston is precisely similar to that of the nrst, so that 
wheu the one is understood, the other requires no explanation. 

The degree of exhaustion will depend upon the workmanship of the pump, the number of strokes 01 
the piston, and the relative capacities of the receiver and barrels ; but perhaps in no case can the vacuum 
in the receiver be made perfect. For the purpose of determining the degree of exhaustion, a mercurial 
gauge is employed, which acts on a similar principle with the common barometer. A glass tube EF, 
rests in a basin of mercury F, and its upper orifice opens into the brass plate SS. When the exhaustion 
of the receiver has commenced, the pressure of the air in the receiver must be less than that of the 
atmosphere without. Wherefore, since the air in the receiver presses the mercury down the tube, and 
the atmosphere pressing on the mercury in the basin forces it up the tube, with the greater force the 
mercury will rise in the tube, and it will rise the higher according to the difference of the density, and 
consequently elastic force of the air in the receiver, and that of the atmosphere. 

AIR-PUMP, Kennedy's Horizontal Doable Cylinder. 

DEsratrpTiox. — In the figure, L L represent the barrels, the enlarged ends of which are let into the 
ix>ard and bolted through to ensure stability. There is one rack; the two pistons being attached to its 
extremities. A portion of the rack is exposed at T. The semi-pinion W, works in cast straps, or 
gudgeons, attached to the bottom of the board by screws, which, passing through, terminate in the 
ruck guides, one of which is seen above. The forward gudgeon is so cast as to receive the end of the 
damp which secures the pump to the table. The semi-pinion works upwards through a slot cut in the 
DOard, and of course between the rack guides. The upper extremities of the guides are perforated *o 



rsceive rollers, against which the back of the rack may work when necessary. None have yet been 
required To the axis of the semi-pinion the handle is attached in the usual manner. The piston may 
be either solid or valved, and the cylinders may communicate with the plates R and B, in the way most 
approved by the maker. In the pump from "which the sketch is taken, the pistons are solid. The 
farther extremities of the cylinders bear female screws, which connect with corresponding male screws 
on the block. On the posterior portion of each block is cut a female screw ; the male of which bears 
the valve V V, of course opening inwards. On those portions of the blocks which project into the 
board are cut male screws bearing valves opening outwards. Perforated nuts over these secure the 
blocks to the board, and the valves against injury. At V V is attached the tube leading from the 
plates. D is the screw for restoring atmospheric pressure. The general stop-cock S, connects this with 
the parallel tube which, bearing the gauge-cock S', forms at pleasure a communication between the 

The original of the figure both exhausts and condenses. The remaining letters refer to the parts used 
in condensing. This is effected by simply connecting, by means of tubes under the board, the valves 
F', F, with a third tube passing upward to the stop-cock K. Then the air drawn in at K, will be 
condensed in a receiver screwed on C. The condensing gauge is borne by the screw G. This 
instrument is furnished thus with all the facilities for exhaustion, transfer, and condensation, without 
any shifting of parts. 

AIR-PUMP. See Engines. 

AIR-PIPES, an invention for clearing the holds of ships and other close places of their foul air. 
The contrivance is simply this : a long tube, open at both ends, is placed with one end opening into 
apartment to be ventilated, and the other out of it. The air in the outer end of the tube is rarefied 
by heat, and the dense air from the hold comes in to supply the partial vacuum, the escape of the 
foul air in the hold being supplied by fresh air introduced through an opening above ; and this process 
is carried on until the air becomes everywhere equally elastic. 

AJUTAGE, a tube fitted to the mouth of a vessel for the purpose of modifying the discharge of 

ALARMS. Machines intended to give notice of danger, as from fire, from fire-damp, from lowness 
of water or excess of pressure in steam boilers, &c. Automatic fire alarms depend in general on 
some arrangements of strings traversing behind the wainscot and ceiling, which if burned off detach 
some mechanism connected with a bell, by which an alarm is given ; the expansion of metal wire or 
rods is also applied for the same purpose. Burglar alarms are sometimes employed by drawing 
strings across passages, connected with alarm bells, or the bells are attached to doors and windows 
in such a manner that a slight opening of the same may cause them to strike. 

For an alarm showing the presence of fire-damp, M. Chuart has made use of a ball or globe, con- 
tained in a chemical solution highly sensitive to 
any deterioration of the atmosphere, and acting 
upon a lever, which sets an index in motion, and 
thus shows the vitiated state of the atmosphere, 
whether in a mine or elsewhere, long before the 
common air can be so saturated with gas as 
to explode on the application of light. M. Chuart 
has added to his invention an alarum bell, which 
is struck by the lever when the ball is thrown oft 
its equilibrium by the vitiated state of the atmos- 

Fig. 7 is an illustration of a method proposed 
to give notice of the lowness of water in boilers. 
A is a float attached to a stem or rod w T hich passes 
upwards through a tube B 1 , and a diaphragm, B 2 , 
fixed within that tube, and terminates in a conical 
top, which fits into the hollow pipe C, of the steam 
whistle D. The lower end of the whistle D is 
passed through an orifice in the top of the boiler, 
(indicated by the letters a a,) and screwed into the 
top of the tube, which is thus kept steady, if in a 
vertical position. E is a collar attached to the stem 
of the float, near the top, which, catching against 
the plate B a , on the fall of the stem or rod A, pre- 
vents it from descending further. When the water 
falls below the safety-line, and the float along with 
it, the descent of the stem of the float opens the 
pipe C of the whistle, and allows the steam to es- _ 
cape, which, impinging against the bell H at top, ^2 
produces the alarm required. In Dunn's alarm for 
boilers, the falling of the water below the proper 
level establishes by means of a battery a galvanic 
current, and rings a bell or bells in any part of the 
establishment in which it is desirable that notice 
should be given. — — ~ 

For the transmission of intelligence of fire in cities see "Fire Alarms." 

ALDER. See Woods, varieties of. 

ALLOTS. Basermetals mixed with more valuable ones. See Assay. 



ALMOND-TKEE. See Woods, varieties of. 
ALOES- WOOD. See Woods, varieties of 

ALTIMETER. Beatson's patent, for taking, measuring, and computing angles. Fig. s is a side 
elevation of this instrument. A is a broad ring of brass, to one side or the back of which a telescope 
C, is affixed in a horizontal line exactly coinciding with the centre of the ring. B is a glass tube of 
about the sixteenth of an inch in the bore, which is let into a groove made in the front of the ring, 
and extends all around with the exception of about an inch or two, where a segmental air-tight junc- 
tion piece F, of metal, is inserted between the two ends of the tube, which are left open, and com- 
municate freely with the piece F. The tube is about half filled with mercury, (or other suitable fluid) 
which forms itself into a continuous thread of a crescent shape, with a fixed quantity of air between 
the two cusps. As long as the two fluids are left at liberty, they may of course be shifted round to 
any parts of the circle ; but in the middle of the junction piece F, there is a valve, V (not seen in the 
figure), inserted, which is worked by a spindle and thumb-piece, from the opposite side of the instru- 
ment; and when this valve is closed, the motion of the fluid to either side of that valve is from that 
moment necessarily stopped. The eye-piece of the telescope is provided with darkened glasses to 
save the eye from the glare of the sun, and the field of view is divided in the centre by a wire, to 
show the line of collimation. On the front of the brass ring A, immediately outside of the groove 
containing the glass tube, and on opposite sides of the telescope, there are two quarter circle scales, 
R, and L, engraved. Both of these scales have their zero points on the same line with the axial line 
of the telescope, but the numbers in R run upwards from to 90, while those in L run downwards 
from to 90 ; the 90° in the one case (R) representing the zenith, and in the other the nadir. These 
scales are subdivided by two verniers, D D. The mode of using the instrument is as follows : The 
observer first releases the alcoholic or other fluid in the tube B from the pressure of the columns ot 
air at each end, by turning the thumb-piece from left to right ; he 
then directs the telescope towards the sun or other object whose 
altitude it is desired to ascertain, and brings the cross-wire into 
contact (so to speak) therewith ; which having done, he turns the 
thumb-pwce the reverse way, which fixes the mercury at the exact 
level it had attained at the moment of contact, the column of air 
in B pressing on the mercury at each end, and thus necessarily 
preventing the slightest displacement. 

The observer next proceeds to read off the indications furnished 
1 by the two scales of the instrument ; he sets first down the numbers 
on the left-hand scale R, which come opposite to the top fine oJ 
the fluid on the left-hand side, and then the numbers opposite the 
top line of the fluid on the right-hand side ; which done, he adds 
the two sets of numbers together, and divides by 2, which gives 
the required altitude. 
For example ; if the 

Left altitude be 
Right altitude 

The sum divided 

46 '20 
47° 40' 


Would give for the desired altitude 


The necessity for taking a mean of the two readings arises from 
the liability of the fluids to expansion, for were no change to take 
place in their thermoiuetrie condition after the contact, the num- 
bers would remain necessarily alike on both sides. 

The better to show to the eye the movements of the fluids in the tube, the bottom of the groove G 
may be stained of a red or some other bright color. 

The "Universal Altimeter" may be contained in one framework with any of the ordinary sea and 
land surveying instruments ; as is exemplified in the fig., where it is shown combined with a common 

AMBOYXA-WOOD. See Woods, varieties of. 

ANALYSIS. See Assay. 

ANASTATIC PRINTING. (The term " Anastatic " means rising up, or a reproducing as it were, 
and very significantly does the name express the result; for by it any number— thousands upon thou- 
sands — of reproductions of any printed documeut may be obtained, each of which is a perfect fac- 
simile of the original, no matter how elaborate the engraving may he, or how intricate the design.) 

The print of which an Anastatic copy is required is first moistened with very dilute nitric acid, (one 
part of acid to seven of water,) and then being placed between bibulous paper, all superabundance of 
moisture is removed. The acid being an aqueous solution, will not attach itself to the ink on the 
paper, printers' ink being of an oily nature ; and if the paper thus prepared be placed on a polished 
sheet of zinc and subjected to pressure, two results follow :— in the first place, the printed portion will 
leave a set-off or impression on the zinc ; and secondly, the nitric acid attached to the non-printed 
parts of the paper will eat away and corrode the zinc, converting the whole, in fact, into a very shal- 
low stereotype. The original being removed (perfectly uninjured), the whole zinc plate should next 
be smeared with gum-water, which will not stick to the printed or oily part, but will attach itself tc 
every other portion of the plate. A charge of printers' ink being now applied, this in its turn only 
attaches : tself to the set-off obtained from the print. The final process consists in pouring over the 



plate a solution of phosphorous acid, which etches or corrodes more deeply the non-printed portion of 
the zinc, and produces a surface to which printers' ink will not attach. The process is now com- 
plete, and from such a prepared zinc plate any number of impressions may be struck off. 

The Anastatic process is not only applicable to the copying of the impressions made with printers 
ink, but any other inks however, even the most fugitive, may be adapted to this operation ; and hence, 
without some safeguard, the dishonest practices to which the Anastatic process might be applied would 
be numerous. The paper invented by Messrs Glynn & Appel afford this safeguard. It consists merely 
in impregnating or dying the pulp of which the paper is made with an insoluble salt of copper. After 
a series of experiments, the patentees preferred phosphate of copper to any other salt ; and for this pur- 
pose sulphate of copper and phosphate of soda are successively mixed with the pulp, which, of course, 
produce an insoluble salt, the phosphate of copper. Besides this, a very small portion of a peculiar oily 
and non-drying soap is introduced, which affords a double protection. Should the forger attempt to 
submit a note or check printed on the patent paper to the Anastatic process, a film of metallic copper 
separates between the paper and the zinc, not only preventing a set-off, but cements the paper so 
strongly that the paper must be destroyed — it can only be removed in small pieces. 

ANACLASTICS. That part of Optica which considers the refraction of light, and is commonly called 

ANCHOPt. A heavy curved instrument, used for retaining ships in a required position. The forms 
of anchors, and the materials of which they are made, are various. In many parts of the East Indies 
the lower part of the anchor is formed of a cross of a very strong and heavy kind of wood, the extrem- 
ities of which are made pointed. About the middle ol t,ach arm of the cross is inserted a long bar of 
the same wood, the upper ends of which converge to a point, and are secured either by ropes or an iron 
hoop, and the space between the bars is filled up with stones to make the anchors sink more deeply and 
readily. In Spain, and in the South Seas, anchors are sometimes formed of copper, but generally in 
Europe they are made of forged iron. Anchors may be divided into two classes — mooring anchors, and 
ships' anchors. Mooring anchors are those which are laid down for a permanency in docks and harbors, 
ana are considerably heavier than ships' anchors, from which they differ in form, having sometimes but 
one arm, and sometimes, instead of arms, having at the extremity a heavy circular mass of iron and no 
stock : these latter are called mushroom anchors. The general form of ships' anchors is shown in the 
annexed figure. There is a long bar of iron, a called the shank, from the lower extremity of which 
branch two curved arms b b in opposite di- 
rections, and forming an angle of 60° each 
with the shank. Upon each arm towards 
the end, is laid a thick triangular piece of 
iron ce, termed the fluke. In the upper 
end of the shank is an eye, through which 
passes a ring d, to which the cable is at- 
tached. The stock e is composed of two 
strong beams of wood, embracing the 
shank, or an iron rod passing through the 
shank. The stock stands at right angles 
to the plane of the arms, and serves to 
gnide the anchor in its descent, so as to 
cause one of the flukes to enter the ground. Ships aro generally provided with three large anchors, 
named the best bower, the small, and the sheet anchor ; a smaller anchor, termed the stream anchor ; 
and another, still smaller, named the kedge, which latter has generally an iron stock passing through 
an eye in the shank, secured thereto by a key, or forelock, which admits of its being readily displaced : 
its principal use is in changing the position of a ship in harbor, and in an operation termed kedging. 
From the great mass of iron in large anchors, (some weighing from 3 to 4 tons,) the perfect forging of 
them becomes a matter of much difficulty ; as from the great heat necessary to weld such masses, the 
iron is liable to become " burnt " as it is termed. "Workmen also cannot always observe what is going 
on in the forge, where the iron is exposed to ignition from the blasts of the bellows, or to the presence 
of sulphur in quantity among the coals. When the welding of a large mass, like the shank of an an- 
chor, is to be completed by the sledge-hammer, the workmen are subjected to a scorching heat radiat- 
ing therefrom, which renders it impossible to make a very close inspection, and the consequence fre- 
quently is, the beating up of cinders within the body of the iron. To this cause, and to burning, may 
be often attributed the breaking of anchors, followed too frequently by a distressing loss of lives and 
property. Many attempts have been made of late years to construct anchors not liable to these defects, 
by dividing the mass into separate parts, and by a more judicious arrangement. 

Figs. 10 and 11 represent the two most popular forms 
of anchors, Porter's and Bloomer & Co.'s. In both, the 
difficulties of the welding the shank to the arms is obvi- 
ated. The construction of Bloomer & Co.'s is as follows : 
The arms or flukes of the anchor are made in two separate 
pieces, or plates of iron of the entire size required, which MM 
are bent to the required sweep, or angle, and secured to the 
shank by a bolt at the crown. The palm and toggle are 
constructed in one solid piece ; the toggle (or horn) being 
bent into the required form, is passed through, between 
the two plates, and secured in its position by them ; the 

point of the palm and the two pointed ends of the plates are then welded together at one heat, which 
completes the work. The shank is made of one solid piece, and is inserted between the plates of the 
flukes, (instead of the flukes being inserted between the two welded jaws, as fig. 10,) and is secured by 
a crown bolt. 



It will thus be seen that this anchor U 
formed with only two welding heats, (viz., 
at each point of the fluke,) and those at 
the places least liable to accident, and of 
less vital importance in case of fracture 
than any other part of the anchor. 

One differing materially in form and 
construction from the ordinary anchor 
was invented by Mr. R. F. Hawkins, and 
is represented in the subjoined engravings. 
The shank of the anchor a is forked at 
the lower part or crown, into two parts 01 
loops b and c, in each of which is formed 
a hole or eye ; between the loops is a 
block of iron d, termed a crown-piece, 
having a circular aperture to receive the 
urma and a square aperture at right angles to the former, into which is screwed a stout bar of iron e, 

termed a toggle, projecting 
equally on each side of the 
crown-piece ; on the end of 
the crown-piece, opposite to 
that in which is inserted 
the toggle, is a ring, f for 
the buoy rope. The arms 
g h are formed in one piece, 
and before the palms ii are 
attached, one end of the arms 
must be passed through the 
eyes in the loops of the shanks 
and through the eye of the 
crown-piece ; the palms are 
then to be put on, and must 
both lie in the same plane ; 
after which the arms are to 
be curved in the same plane 
with the palms. The crown- 
piece is firmly keyed to the 
arms, and the toggle must be 
of such a length and form as 
to make it bear firmly against 
the fore part of the fork in 
the shank, so as to prevent 
the crown -piece and arms 
from turning round upon it, 
and to retain them at an an- 
gle of 50° with the shank. When the an- 
chor is let go, oi2e end of the toggle will come 
in contact with the ground, which puts the flukes 
in a position to enter; and when the strain is 
upon the cable, that end of the toggle which is 
upwards comes in contact with the throat of 
the shank, and sets the anchor in the holding 
position, as shown in perspective at fig 14. 
The advantage of this mode of constructing an- 
chors is, that both arms take the ground, and 
therefore the weight of metal may be diminished, 
and yet an equal, if not a greater effect be 
obtained ; also, as there is no stock, and no pro- 
jecting upper fluke, there is little risk of fouling, 
as it is termed ; that is, of the cable entwining 
round the arms. 

An anchor upon a similar principle, but of a 
somewhat different construction, was invented 
by Mr. Soames, a front and side elevation of 
which is exhibited in the subjoined cuts. In 
this anchor there is but one fluke o, which is T 
shaped, and works on a pivot in a triangular 
frame, composed of the two sides b and c, forged 
m one piece, and a stay d, which serves as a stock ; f f are loops, or eyes, for the reception of 
the chains that unite the ring g, to which the cable is to be fastened. For general purposes, this an- 
chor is perhaps preferable to the former, it being free from the objection we made to that one, as it 
admits of detaching the arm, which renders it more convenient to stow away ; also, as the shank is 


formed in two parts, instead of one of equal area, they are more easily forged soundly, and consequently 
less liable to breakage. 

The peculiarity of the anchor proposed by W. Rogers, consists in its having a hollow shank, formed out 
of sis bars of iron, of such a thickness as to insure the forging of them perfectly sound for anchors of the 
largest dimensions. Fig. 18 represents a side Tiew of the anchor, and tig. 19 a plan of the stock. The two 
principal pieces a a are bent so as to form a part of the arms or flukes ; the other four are formed into 
a hollow tube 6 b (as shown in section at Fig. 20) for a centre-piece, and the whole are firmly w elded 
together at both ends of the shank. The intermediate parts are secured by strong hoops i i, so that 
every piece must bear its proportion of the entire strain. In place of the usual ring, there is n bolt 
and sliackle c. Figs. 18 and 21, when the anchor is to be used with chain cables ; but when hempen "able* 
are to be used, a ring d is connected to the shackle c by an additional shackle and bolt e. The ? "chor. 

stock f may be formed either of a single piece, or of two pieces hooped together, and is secured in its 
place as follows: The bolt and shackle c being withdrawn, the small end of the shank is passed 
through the eye of the stock/, (which is defended by an iron plate g on each side ;) the collar k is then 
put over, and the stock is keyed up against the hoop i by the forelock key k passing through a hole in 
the shank ; 

jiro improved methods of letting go anchors are described in the Transactions of the Society of Arts. 
The principle is the same in each, and consists in supporting the end of what is termed the standing 
part of the cat-head stopper and shank-painter, by bolts turning upon pivots, and retained in a proper 
position by a catch, which being withdrawn, the bolt turns upon its pivot, and the stopper slips off, by 
which means all risk of jamming the turns of the stopper (as in the common method of letting go the 
running end) is avoided ; the danger to the men on the forecastle is done away, and the anchor can be 
let go at a moment's warning. 

The arrangements in each of these inventions being the same, whether applied to cat-head stoppers 
or shank-painters, we shall therefore 

show one invention as applied to g 1 ^\ L_ _ ^^ _ 

cat-head stoppers, and the other to f , 1 ny/ s ft fl C) J-j j J Q p- 

shank-painters. The subjoined cuts 
show Capt. Burton's method if letting 
go a cat-head stopper, a i the cat- 
head ; k a bolt, turning «pon a 
pivot d; the end c forms an obbque 
plane, and is held down by the 
clamp e turning upon a pivot f the 
clamp being secured by a hasp g and 
pin h. The standing end of the 
stopper, having an eye formed in it, 
passes over the end b of the bolt 
be; the other end of the stopper 
passes through the ring of the anchor, 
and over the thumb-cleat /„•, and is 
made fast round the timber-head /. 
When it is required to let go the 
anchor, a handspike is inserted be- 
tween the thumb-cleat i, so as to nip 
the clamp e, and the hasp ^r is cast off; then, upon withdrawing the handspike, the bolt being no longer 
held by the clamp e, turns upon its pivot d, by the weight of the anchor on the stopper, and the eye kA 
the stopper slips off the end of the bolt 

The following cut represents Mr. Spence's invention for letting go a shank-pairter. Fig. 24 is an 



elevation, and Fig. 25 the plan, a is a cast-iron carriage, bolted through the ship's side, and supporting 
the hook d by a pin or pivot at b : d e a lever turning upon a ceutre /, the end d being formed into a 
nook, -which clasps the upper end of the bolt 6, the lever being retained in the position shown in the 
plan, by a pin g ; h is part of a chain forming the standing part of the shank-painter, and supported bv 
the bolt b. To the other end of the chain is spliced 
the running part of the shank-painter, which passes 
round the shank of the anchor, and is made fast to a -"*■ ® 

timber-head. When it is required to let go the 
shank-painter, an iron bar is inserted into the end e 
of the lever d e, winch is made hollow for the pur- 
pose, and the pin g being withdrawn, the lever is 
turned round its centre until the bolt is released from 
the hook d, when it falls, and the chain end of the 
shank-painter slips off. 

ANGICA-WOOD. See Woods, Varieties of. 
ANEMOMETER. An instrument for measuring 26- 
the strength or velocity of the wind. Among various 
machines which have been constructed for tlus pur- 
pose, the following one has been found to answer very well. It consists of an open frame a c, sup- 
ported by a shaft d, upon winch it turns by the action of the wind upon the vane e. f f are sails, fixed 
to one end of the axis g, and disposed to be influenced by the wind in the. usual manner. Upon this 
axis is also fixed a conical barrel of wood h k, on the smaller end of winch k is attached a line /, with a 
weight appended to it. The wind acting upon the sails, causes the barrel to revolve, and the line to be 
wound up on its superficies. To prevent any retrograde motion, a ratchet wheel o is fixed to the base or 

larger end of the cone, having a clicker falling into the 
notches as it revolves. It is evident that the power of 
the weight will continually increase as the line advances 
towards the base of the cone, as the weight acts at a 
greater distance from the axis or fulcrum ; conse- 
quently, the variable force of the wind may be readily 
ascertained by fixing the line at the smallest end, and 
marking the barrel with spiral lines, as taken up by 
the coiling of the rope round its superficies, placing 
also between the lines numerals to denote the force of 
the wind, which may be calculated with tolerable 
precision upon the principles of the lever. The 
diameter of the cone should be such in comparison 
with its smallest end, that the force of the strongest 
wind should have scarcely sufficient force to brina 'he 
line on to the base of the cone. 

Although the instrument de- 
scribed above gives an accurate 
idea of the comparative force of 
the wind at different times, it 
does not point out the actual 
force exerted on a given surface, 
nor can observations made with 
one instrument in a particular 
place, be compared with obser- 
vations made by another instru- 
ment elsewhere. It is also cum 
bersome, and not portable. In 
the Philosophical Transactions 
for 1775, Dr. land gives a de 
scription of a very ingenious 
portable wind gauge, which nidi 
cates the actual force of the wind 
by the column of water which it will support. This instrument consists of two glass 
tubes a b,cd, which should not be less than 8 or 9 inches long, the bore of each being 
about four-tenths of an inch in diameter, and connected together by a small bent glass 
tube e, of about only one-ninth of an inch bore, to check the undulations of the 
water caused by a sudden gust of wind. On the upper end of the tube a b is fitted 
a thin metal tube /, which is bent at right angles, and has its mouth open to re- 
reive the wind blowing into it horizontally. The two branches of the tube are at 
liberty to turn round a steel spindle g, which passes through two slips of brass h i 
near the top and bottom of the instrument. The spindle is fixed into a block of 
wood by a screw in its bottom. When the instrument is used, a quantity of water 
is poured in until the tubes are about half full, and the instrument being then 
held perpendicularly, with its mouth exposed to the wind, the water will be de 
pressed in the tube ab, and proportionally elevated in the tube cd ; and the dis- 
tance between the surfaces in the two tubes measured by a sliding scale of inches, 
and parts k attached to the instrument, will be the height of a column of water 
which the wind is capable cf sustaining at that tune ; and as a cubic foot of water 



Force of Wind, 

















.52.1 113.6 

.57.3 119.2 

■62.5 124. 

weighs 1000 ounces, or 624, pounds nearly, the 
twelfth part of which is 5 5-24 pounds, therefore 
every inch the surface of the water is raised, the 
force of the wind will be equal to so many times 
6 5-24 pounds on the square foot This instrument 
shows the force, but not the velocity, of the wind ; 
but as the force is as the square of the velocity, if 
the velocity due to a given force be ascertained, a 
table of the velocities corresponding to each inch 
the water is elevated, may be calculated and en- 
graved upon the scale of equal parts. The tible 
at the right, showing the corresponding height, of 
water, velocity of the wind, and the force exerted 
upon a square foot of surface, has been cali-jlated 
from some experiments made by Dr. Hutton. 

BIRAirS ANEMOMETER, (Fig. 28,) is designed 
to register the current of air in mines. Iu the 1— — 
recent report of the Committee appointed by 
the British House of Commons, for inquiring 
into the causes of accidents in coal mines, the 
adoption of some mode of measurement and 
registry, is strongly recommended. In this 
country the same degree of necessity for such 
precautions has not yet been reached, because 
our mines of bituminous coal are mostly shal- 
low, and yield comparatively little of the com- 
bustible gases. In order to displace by fresh 
air these poisonous gases, as also the smoke 
of gunpowder, of lamps, and the products of 
respiration, it is necessary to build a fire in 
one of the shafts of the mine, and to keep it 
np at all times ; so that the draught of the 
furnace shall cause a movement of the stag- 
nant air in the galleries. 

Biram's Anemometer registers these move- 
ments of the air by a combination of wheels 
with indices, similar to a gas meter. It is 
only 12 inches in diameter, and weighs about 
2^ lbs. Any slackening of the furnace, or iu- 
•attention in the furnace man, will be at once 
detected by the registry of this simple appa- 
ratus. The observer has only to record the 
position of the several indices at the first ob- 
servation, and deduct the amount from their 
position at the second observation, to ascer- 
tain the velocity of the air which has passed 
during the interval ; this multiplied into the 
area in feet of the passage where the instru- 
ment is placed, will show the number of cubic 
feet which have passed during the same period. 

ANEMOSCOPE, a machine that shows the course or direction of the wind. 

Of late years instruments have been introduced into observatories for tracing continuously the 
force and direction of winds ; the most common are those by Dr. Whewell and Mr. Osier. In the 
machine as arranged by Dr. W., a windmill fly is constantly presented to the wind in whatever 
direction it may blow, and the fly of course revolves with greater or less rapidity according to the 
velocity of the current. An intermediate train of wheels set in motion by the fly, causes a pen- 
cil to descend over a fixed cylinder, leaving thereon a trace of variable length, according as the wind 
is more or less strong. 10,000 revolutions of the fly causes the pencil to descend only one-twen- 
tieth of an inch. The surface of the fixed cylinder is japanned white, and is divided into 16 or 32 
equal parts by means of vertical lines, the intervening spaces corresponding to 16 or 32 points of the 
compass, and a mark left by the pencil upon one or more of these spaces, shows the direction of the 
wind. The pencil has two motions, the first from above downwards, and this increases in rapidity as 
the wind blows more strongly, and by the extent of its depression registers the whole amount of wind 
that has been blowing. The second motion depends on the changes in the direction of the wind ; and 
the pencil and its frame being earned round by the vane, the direction is registered by this cross move- 
ment. In this arrangement therefore, the vane, the windmill fly, the intermediate train of wheels and 
the pencil, all obey the direction of the wind ; while the cylinder which marks the points of the com- 
pass remains fixed, so that the pencil in descending and moving about with the wind, thus traces an ir- 
regular line on the cylinder. If the fly revolves in the simple proportion of the velocity of the wind, 
the length of line marked by the pencil is proportional to the space which would be described by a par- 
ticle of air in a given direction in a given time, such as one day, taking into account the strength of 
the wind and the time for which it blows. 

In Osier's Anemometer, the force and direction of the wind, and also the amount of rain are regis- 



tered on a paper placed on a board moved by means of clock mechanism. The pressure is measured 
by a plate always directed so as to face the wind. Three pencils are used, of which one registers the 
pressure of the wind in pounds per square foot, another the direction of the wind, and the third tins 
quantity of rain falling in a given time. Each paper registers during the 2-i hours of the day, although 
it may be arranged for longer periods. The whole length of the paper is divided by vertical lines into 
24 equal parts ; at the top is a series of parallel lines, corresponding to the pressure in pounds per 
square foot ; in the centre ore lines corresponding to the cardinal points of the compass, and the lowe 
portion of the paper registers the quantity of rain. 

The method by which the pressure plate is always made to face the wind is a3 follows : a set of 
vanes or sails revolve vertically in a plane at right angles to that of the pressure plate, and drive a cog 
■wheel, which by rolling on a fixed cog circle, turns all the rest of the apparatus round until the vane 
are presented edgewise to the current, then the pressure plate being at right angles to the vanes is actej 
on with full effect. As the vanes turn in the direction of the wind, a spiral worm on the shaft raises 
or lowers a nut, from which hangs the arm carrying the middle pencil, which thus traces the direction 
of the wind on one of the long lines of the register paper if the wind be from one of the cardinal 
points, or a mark between these lines if it be blowing from intermediate points, such as N.N. TV., N."\V. 
&c. The rain after falling into a vessel on the roof flows into one of the two divisions of a gauge 
balanced on an axis and supported by a second balance. As the water accumulates this second Salance 
begins to descend, and so raises the upright rod to which a lever is attached which causes the pencil to 
rise. "When this quantity becomes equal to a certain depth of rain, or to a certain number of cubic 
inches on a fuot square, the small gauge oversets, the water is discharged, and the other compartment 
of the gauge is brought under the pipe The pencil then returns to its first position at the bottom of 
the paper, and begins to rise on the scale as the rain is collected. In a trace of this kind it will be 
seen that the more rapidly the rain falls, the sharper will be the angles formed by the trace of the pen- 
cil ; but if the rain be slow and gradual, the elevating or diagonal lines will be drawn out to a con- 
siderable length. 

ANEROID BAROMETER. The principle of the instrument is dependent upon the action of the at- 
mospheric weight upon the exterior of an exhausted or partially exhausted case of thin metal, the top 
of which, being slightly flexible, is so contrived as to convey indications of the minutest changes in the 
atmospheric column to a graduated dial, upon which the readings are exhibited as in the ordinary 
wheel barometer. 

The original instrument of M. Conte bears a resemblance to a watch ; it consists of a strong iron Of 
brass box a, in the vertical section Fig. 29. To the edges Fisr. 29. 

of this box, a very thin and flexible steel cap b is fitted 
with great accuracy, cc are a series of springs acting 
between the bottom of the box and its flexible top, so as 
to press the latter up. A small cylinder is fitted at d, by 
which the case, 'when exhausted, may be hermetically 
closed. The dial is placed immediately over the top of 
the case, and is pierced in the centre for the passage of a 
central tube e, earring an index-needle /, the whole be- 
ing surmounted by a concave glass. It is obvious that 
If the space enclosed by the case is exhausted, the flexible top or cap b being acted upon by the unbal- 
anced pressure of the atmosphere, will fell, and compress the supporting springs c ; and the converse takes 
place when any diminution in the atmospheric pressure occurs. By simple mechanism placed in the 
tube e, this movement of the cap may be communicated to the index-needle, which will thus register 
the variations in the columnar pressure. It is stated that the thermal changes of the atmosphere dis- 
turbed the action of the instrument, and eventually caused M. Conte to discard it as useless. 

The objection of the want of any temperature compensation, M. Vidi has sought to remove in the 
Aneroid of the present day. One of the great features which were introduced at this time, was the cir 


rular corrugation of the flexible diaphragm ; and thus a larger and more available range of movement 
was obtained without danger of rupture. Fig. 30 is a half-size plan of the instrument as now made, un- 
der the superintendence of Mr. Dent ; Fir 31 is a corresponding side elevation. The vacuum chamber 


is represented at a ; its top and bottom are formed of disks of thin circularly corrugated copper, held 
together by a circumferential strip of plain metal, as shown in the detail fig. 32, which is a vertical sec- 
tion of the chamber detached A strong brass stud b, is attached to the upper diaphragm of the 
chamber, having a slot on its end, through which a small projecting pin c, formed on the lever-plate a 
projects, the attachment being effected by a pin passed transversely through the slotted portion of the 
stud, immediately over the pin c. The plate d, which acts as a lever in communicating the movements 
of the diaphragm, rests upon two pillars e, carried by the supporting base-plate of the vacuum chamber, 
as fulcra. The projecting lever portion f conveys the movement by a joint at g, which is linked to a 
rocking spindle carrying the lever h, connected to the arbor of the index-needle by a fine chain which 
winds upon it, like the main-spring chain of a watch upon the spring box. In the iuterior of the va- 
cuum chamber, a single helix is fixed upon the base-plate, so as to abut against the lower surface of 
:he lever at z, and thus preserve the two diaphragms of the chamber from actual contact. 

To set the instrument to indicate the same scale as the mercurial barometer, the arrangement given 
full size in Fig. 33 is adopted, to form the connection between the main lever and the index arbor. The 
link from the end of the main lever is joined to an eye at a, on a stud formed upon the end of a metal 
bow piece 5, the contrary end of which is attached to the lever h, before described. The whole of 
these parts are carried by a nicely adjusted rocking spindle c, working on centres in the frame /. The 
office of this contrivance is to afford a means of adjustment for the index movement by the two screws 
in ?t, one of which elevates or depresses the eye o, whilst the other sets it in or out from the centre of 
the rocking spindle, to give more or less leverage, as may he required to suit the barometrical scale. 
The connection between the index arbor and the lever apparatus being by a flexible chain, its move- 
ment can act only in one direction in bringing round the index, and a tine hair spring is attached to 
give the return movement. 

The tube by which the exhaustion is effected is at o. The process of exhausting, as specified by the 
inventor in connection with the original plan, is as follows. A little solder is placed round the aper- 
ture for the exhaust, in which a flat-headed pin is set. so open as to admit the air to pass. The dia- 
phragm is compressed to its proper position by means of a board, and is then soldered to its 
box- The whole is afterwards placed under an air-pump receiver, having an air-tight stuffing-box, 
through which a rod, carrying the heated soldering-iron is passed. When the vacuum is obtained, the 
soldering-iron is pressed down to melt the solder round the peg, and close the opening. 

A simple mode of adjusting the instrument by a standard ba- 
rometer is obtained by a screw-stud projecting through the back of 
the instrument, iu connection with the reacting spring at i, the tension 
of which may thus be varied to the extent required. By a simple, ar- 
rangement, the vacuum case is itself made to afford its own tempe- 
~i rature correction, without the addition of a particle of mechanism. 
Previous to the exhaustion of the vacuum chamber, the top and bot- 
tom diaphragms are both perfectly horizontal ; but when exhausted, 
they each take the curve shown in the section fig. 32, and the dotted 
lines represented as running nearly even with the corrugated surfaces 
indicate the position they will assume when a portion of gas is introduced to play the important part of 
a compensator for the disturbance to which the index would be liable from changes of temperature. 
The expansion of the contained gas, arising from the disturbing cause itself, counteracts the loss of 
elastic force produced by the same cause iu the diaphragms and other parts of the machinery. The 
external atmosphere is continually endeavoring to press down the diaphragm, whilst the helix beneath 
the lever is as continually acting to keep it up. An increase in temperature expands the contained gas, 
which thus diminishes the effect of the external atmospheric pressure, and corrects the disturbance 
arising from the expansion of the various levers and connections, which would otherwise indicate upon 
the dial a greater amount of movement than is actually due to the atmospheric change. 

ANGLE, in Geometry. If two lines drawn on a plane surface are so situated that they meet in a point, 
or would do so, if long enough, they form an opeuing which is called an angle. When one line meet- 
ing another makes the angles on both sides equal to each other, then these angles are each called a 
right augle, and in this case the one line is said to be perpendicular to the other. In the common lan- 
guage of workmen, the one line is said to be square with the other; and if the oue line be horizontal, 
the perpendicular is said to be plumb to it. The arc which measures a right angle, is the quarter of the 
whole circumference, or is a quadrant, and contains 90 degrees ; any angle measured by an arc less 
than this, is acute, (sharp,) and if by an arc greater than a quadrant, obtuse, (bluut.) 
ANIMAL KINGDOM, materials from — used in the mechanical and ornamental arts. 
Porcelanous and nacreous shells, bones, etc. — The hard solid substances derived from the Animal King 
dom, are parts of the external or internal skeletons, as shells and bones ; or of the instruments of sus- 
tenance and defence, as horns, hoofs, nads, claws, and teeth : these, together with the various coverings 
of animals, "whether hair, feathers, or scales, are alike composed of animal aud earthy matters, almost 
exclusively albumen, gelatine, and lime, combined in various proportions, and with a structure more or 
less interspersed with anim al fibre. Many of these are either formed by the deposition of. successive 
annual Layers, or they are altogether yearly renewed. 

A brief consideration of the chemical difference between then- component parts, and of their respective 
proportions, in such as are used in the arts, will show the reasons for their various characters, and differ- 
ent treatment with tools. 

Albumen, the principal ingredient of these animal substances, and which exists in the purest form in 
the white of eggs, is hardened by a degree of heat less than the boiling temperature of water,' and i* 
uisolul/le in the same. Gelatine, of which jelly and glue are different examples, is softened by heat, anc 
tendered fluid by the addition of water: both are easily cut and scraped, in all their various stages firon 


Foft to hard, and during this change they contract very materially, but 'without entirely losing their ela* 

The earthy matters of the animal solids, principally the phosphate and carbonate of lime, are widely 
different from the foregoing, and also from the substances of the woods and metals. They are inelastic, 
and often crystalline, and therefore incapable of being cut into shreds or shavings ; as when they are 
divided, they become smaller fragments or particles which are always angular : they are comparatively 
uninfluenced by water or small changes of temperature, and are incapable of contraction. 

When the earthy and crystalline structures prevail, the animal substances are harsh, incapable of ab 
sorbing moisture, or of alteration of size or form ; when the animal and fibrous characters prevail, they 
are easily cut, and they absorb moisture, soften, and swell. Enamel of teeth, the hardest of the class, 
contains from 2 to 3J per cent of animal matter, (Berzelius.) Porcelanous shells are nearly similar. 
Xacreous shells, U per cent, (Hatchett.) Ivory, 24 per cent, (Ure ;) 25 per cent, (Herat Guillot.) 
Bone, 33 per cent, (Berzelius.) Horn, is coagulated albumen and lime, with j per cent of phosphate oi 
lime, (Ure.) Tortoiseshell is nearly the same as horn. The horn of the buck and hart aic intermediate 
between bone and ordinary horn, (Ure.) 

In some of the shells, the quantity of animal matter is so small, and the lime is in so haid and compact 
a form, that they are very brittle, partially translucent, generally they have smooth surfaces, and are in- 
capable of being cut with a knife or tools ; such shells are called porcelanous, from their resemblance to 
porcelain, they include most of the univalve shells, such as the whelks, limpets, and cowries. Most ol 
these can only be worked upon after the manner of the lapidary, with emery and other gritty matters 
harder than themselves, by wdiich means they are cut and polished, as will be explained in speaking ol 
that art ; by analysis, porcelanous shells are considered closely to agree with the enamel of the teeth. 

The nacreous shells, thus named from nacre, the French for mother-of-pearl, are most commonly known 
in the shells of the pearl-bearing oyster of the Indian Seas, (Ostrcea margaritifcra,) but they include the 
generality of the bivalve shells, as the various 03-sters, muscles, itc. ; within they are smooth and iridescent, 
without they have a rough coat or epidermis. 

These kinds contain a larger proportion of animal matter, which is considered to be arranged in alter- 
nate layers with the carbonate of lime ; and as these shells also are impenetrable to water, they neither 
shrink nor swell. The pearl shells are less frangible and hard than the porcelanous shells, and they ad 
mit of being sawn, scraped, and filed, with ordinary tools ; but they are harsh, scratchy, and disagreeble 
under the operation. 

The beautiful iridescent appearance of the pearl shells is attributed to their laminated structure, which 
disposes their surfaces in minute furrows, that decompose and reflect the light ; and owing to this lamel- 
lar structure, they also admit of being split into leaves, for the handles of knives, counters, and the pur- 
poses of inlaying. As the pieces are very apt to follow, and even to exceed the curvature of the surface, 
splitting is nox much resorted to, but the different parts of the shell are selected to suit the several 
purposes as nearly as possible ; and the excess of thickness is removed upon the grindstone in preference 
to risking the loss of both parts in the attempt to split them. 

The usual course in preparing the rough pearl shell for the arts, is to cut out the square and angular 
pieces with the ordinary brass-back saw, and the circular pieces, such as those for buttons, with the an- 
nular or crown saw, fixed upon a lathe mandrel. The sides of the pieces are then ground flat upon a 
wet grindstone, the edge of which is turned with several grooves, as the ridges are considered to cut more 
quickly than the entire surface, from becoming less clogged with the particles ground off. The pieces 
are finished upon the flat side of the stone, and are then ready for inlaying, engraving, and polishing, 
according to the purposes for which they are intended. Cylindrical pieces are cut out of the thick part 
of the shell, near the joint or hinge, and rounded upon the grindstone, ready for the lathe, in which they 
may be turned with the ordinary tools used for ivory and the hard woods. 

The following are considered by an experienced dealer to be the respective qualities of the pearl shells. 
Tr 3 Chinese, from Manilla, are the best ; they are fine, large, and very brilliant, with yellow edges. 
Singapore, fine large shells, dead-white. Bombay, a common article. Valparaiso, also common, with 
jet-black edges. South Sea pearl shells, common, with white edges. 

The very beautiful dark-green pearl shells, are known as ear-shells or sea-ears ; they are unlike the 
others in form, being more concave, and with small holes around the margin, and are the coverings of 
the Haliotis, found in the California!!, South African, and East Indian Seas. Cameos are cut in the conch 
shell, Strombus G-iiias, of the southern coast of America, and the West Indian Islands. 

Mr. E. H. Bond states that he has seen the Chinese work the largest of known shells, the 
Cliama Gir/as of Linnams, the Tridncna Gic/as of Lamarck, into snuff-bottles, tops of walking-sticks, 
bangles, (a kind of bracelet.) and similar articles, some of which he possesses. The shell is a bivalve and 
not nacreous, generally white, sometimes pale blue ; it may be beautifully polished, and is less readily 
scratched than mother-of-pearl ; its localities are the Indian Seas, New Holland and the Red Sea, but the 
largest are obtained from Sumatra, one pair from whence, described in Sir Joseph Banks' MSS. Library, 
is said to weigh, the one valve 285, the other 222 pounds, but the more usual weight is about 100 pounds 
each valve. Mr. Bond considers the useful portions of the shell, already prepared, might be obtained 
from China. 

In the bones of animals, the earthy ami animal matters are more nearly balanced ; they are therefore 
less brittle than the shells, but prior to being used they require the oil with wliich they are largely ire- 
prcgnated to be extracted by boiling them in water, and bleaching them in the sun, or otherwise. This 
process of boiling, in place of softening, robs them of part of their gelatine, and therefore of part of their 
elasticity and eontractibility likewise they become more brittle, and having a fibrous structure, they 
tireak in splinters. 

The forms of the bones are altogether unfavorable to their extensive or ornamental employment: 
'/lost of them are very thill and curved, contain large cellular cavities for marrow are aie interspersed 
'ith vessels that are visiUe after they are worked up i:'to brushes, spoons, and articles of common 


turnery. The buttock and slrin bones of the ox and calf, are almost the only kinds used. To whiten the 
finished works, they are soaked in turpentine for a day, boiled in water for about an hour, and then 
polished with whiting and water. 

Bone is far less disagreeable under the tools than the pearl shell, but it is nevertheless hard, harsh, and 
chalkv ; the screws cut on bone are imperfect and soon injured. It is harder, often whiter, but muob 
less pleasant to work than ivory, which beautiful material will be treated of separately. 

Horn. — In the English language we have only one word to express two quite different substances ; 
namely, the branched bony horns of the stag genus, and the simple laminated horns of the ox genus, and 
other kindred genera. 

The bony horns are called in the French hois, from their likeness to the branch of a tree ; they are 
annually renewed. 

The other sort of horn, to which the French appropriate the term come, and which is the subject of 
our present inquiry, is found on the ox, the antelope, the goat, and sheep kinds. 

These two kinds will be considered separately. 

The stag-horn closely resembles the ordinary solid bones, both in its chemical characters, and also in 
structure, as it is spongy and cellular in its central parts. The hom is sawn into pieces, filed to the re- 
quired shapes, and used without any further preparation, the natural rough exterior of the hom being 
left in the original state; its appearance is neat and ornamental, and from its uneven surface is very 
suitable for the handles of knives, and other instruments requiring to be held with a firm grasp. 

When short pieces of stag-horn are used entire, as for the handles of table-knives, the hollow cellular 
part is concealed by the addition of the metal cap, and those parts of the white internal substance, which 
are necessarily exposed, are browned with a hot iron, or the flame of a blowpipe, so as nearly to match 
the other parts. 

The horns of the ox tribe are deposited in annual layers upon the bony cores that project from the 
foreheads of the animals ; whence it results, that the general form of the horn, (neglecting its curvature,) 
is conical, the portion beyond the core is solid, and the other extremity tapers off so as to terminate at 
the base in a single plate, or extremely thin edge. 

Horn consists almost entirely of animal matter, chiefly membranous — namely, coagulated albumen with 
a little gelatine, and an inconsiderable portion of phosphate of lime ; had the horns much more earth they 
would be brittle like bones, had they much more gelatine they would be soluble like jelly or glue ; as 
they are constituted, the quantity of gelatine is only sufficient to allow them to be considerably softened 
by a degree of heat not exceeding that of melted lead, after which they may be cut open with knives or 
shears, flattened into plates, divided into leaves, and struck between dies like metal. Their gelatine 
serves as a natural solder, so that neighboring surfaces, when perfectly free from greasy matter, may be 
permanently joined together by moisture, heat, and pressure : the union becomes perfect, but horn being 
a cheap material, the process of joining it is seldom practised. 

The straight conical horn of the rhinoceros is also occasionally used ; it is solid, and formed as of a 
group of hairs cemented together: the transverse section of the upper part of the hom exhibits small dots. 
The horns of the chamois and antelope, and those of some other animals, are generally looked upon as 
natural curiosities, and are only polished exteriorly, without any strictly manufacturing process being 
applied to them. 

The first step in operating upon horn is the separation of the bony core, winch is effected by macera- 
ting the horns in water for about a month, when, from the putrefaction of the intevmediate membrane 
the core may be readily detached ; this is not thrown away, but burnt to constitute the bone earth useij 
for the cupels for assaying gold ami silver. 

The solid portion or tip of the hom is usually sawn off, and the remainder, if not cut into short lengths, 
is softened by immersion for half an hour in boiling water ; it is then held in the flame of a coal or wood 
fire, until it acquires nearly the heat of melted lead, when it becomes exceedingly soft, after which it ii 
slit up the side with a strong pointed knife, and opened out by means of two pairs of pincers applied to 
the edges of the slit ; and lastly, the "flats" are inserted between iron plates previously heated and 
greased, which are squeezed tight in a kind of horizontal frame or press by means of wedges ; wooden 
boards may be used. 

1 or general purposes, as for combs, the pressure should be moderate, otherwise, in the language of 
the workman, it breaks the grain, or divides the laminae, and causes the points of the teeth to split ; but 
great pressure is purposely used in the manufacture of the leaves for lanterns, which are afterwards 
completely separated with a round-pointed knife, scraped, and polished. The heat and pressure when 
applied to the light-colored horn render it almost transparent. 

An improved mode of " opening hom" was invented by Mr. J. James, by which the risk of its being 
scorched or frizzled over the open tire is entirelv removed ; he employs a solid block of iron with a 
conical hole, and an iron conical plug : these are heated over a stove to the temperature of melted lead, 
and the horn, after having been divided lengthwise with a saw or knife, is inserted in the hole, the 
plug is gradually driven in with a mallet, and in the space of about a minute the horn is softened and 
ready for being opened in the usual manner. 

In making drinking-horns, and some few other turned works, the material is cut to the appropriate 
length, brought to the circular form, and allowed to cool in the mould ; the process is similar to that 
just described, although the old methods of the open fire and wooden cones are commonly used. The 
horn is then fixed in the lathe by its larger end, and turned on its inner and outer surface, and the 
groove, or chime far the bottom, is cut with an appropriate tool A thin plate, previously cut out of a 
flat piece of horn with a crown-saw, is dropped into the horn, and forced into the groove, after the horo 
has teen sufficiently heated before the fire to allow the necessary expansion ; in cooling, the contraction 
fixes the bottom water-tight. 

As an illustration of the peculiar properties of horn, and a mode of its employment in the lathe, may 
be mentioned the expanding snake : tins toy is well known to consist of a conical piece of horn, tlw 



one end of which is carved to represent the head, and the remainder is cut into a single spiral shred, st 
as to admit of great expansion, in imitation of the body of the reptile. I find the elastic portion of tht 
one before me to measure, when compressed, barely one inch and a quarter in length, and that it expands 
to upwards of tliree feet and a half, or thirty-five times : no mean proof of the elasticity of the 

In making this trifle, the material is first turned to a conical form, after which a hole of about one- 
eighth or one-sixth of an inch diameter, is pierced from the tail almost through the head ; the horn is 
then soaked for about two days in cold water to soften it, and the spiral incision or screw is made al 
one single cut, by means of a tool extending from the centre to the circumference ; the cutter is not 
required to be verv thin, as the shaving will bend away to make room for the same. One of the three 
following modes of pioceeding is recommended in the Manuel da Tourneur. 

First, by the employment of a sliding rest, adapted to cutting screws, by which the tool is traversed, 
or guided mechanically along the horn luring the rotation of the mandrel of the lathe ;. and to prevent 
the fracture of the toy during its construction, a stick of wood, with a button on the end of it, is ]>ut up 
the aperture, to receive and support the spiral as it is produced. 

Another method is by the employment of a lathe with a traversing or screw-cutting mandrel, upon 
which latter the horn is fixed, the tool being kept stationary in the slide-rest. Both methods require 
expensive apparatus, the principles of which will be explained in the article on screw-cutting tools. 

The third plan is extremely simple ; and appears, on inspection, to have been the one pursued in 
this instance : it is ascribed to the German toy -makers. The horn is prepared as before, but the lathe 
and slide-rest give way to the ordinary carpenter's brace, which carries the piece of horn, as in Fig. 30. A 

W1WM 1 — 

BT'all tool is fixed in the vice or bench; it consists of a piece of wood, to which is screwed a hardened 
ateel plate about one-twelfth of an inch thick ; it has a hole equal to the diameter of that in the horn, for 
the passage of the supporting wire ; the plate is divided radially, the one edge is sharpened very 
keenly, and bent so much in advance of the other, that their difference of le^'el or agreement, shall be 
equal to the intended thickness of the continuous shaving of the body of the snake, and therefore the 
projecting edge assimilates to the mouth of a plane : the last processes, in every case, being to carve 
the head and to attach a little piece for the end of the tail 

It is necessary the coils of the snake should be of a conical form, or dished, as in Fig. 3 1 , instead of being 
quite flat, as it increases the strength of the toy ; this is accomplished by making the cutting edge oi 
the tool oblique to the axis of the snake ; Fig. 32 shows the tool for the lathe. The several details are 
too simple to require further explanation. 

The handles for knives, razors, and other works moulded in horn, are thus made : the horn is first cut 
into appropriate pieces with the saw, and when heated these are pared witli a knife or spokeshave, to 
the general form and size required ; in this state horn works as easily as a piece of deal : after having 
fceen pared, the pieces are pressed into moulds. 

An idea of the moulds will be conveyed by imagining two dies, or pieces of metal, parallel on their 
ftuter surfaces, and with a cavity sunk entirely in the one, or partly in each, according to circumstances : 
Hie cavities made either straight, curved, twisted, rounded, bevelled, or engraved with any particular 
device, according to the pattern of the work to be produced. 

The pressure is applied to the dies, by enclosing them in a kind of clamp, made like a very strong 
pair of nut-crackers, but with a powerful screw at the end opposite to the joint ; the mould, dies, and 
horn, are dipped into boiling water for a few minutes, and then screwed as fast as possible immediately 
on removal from the same, and in about twenty minutes the work is ready for finishing ; some handles 
are made of two pieces joined together. 

On referring to French authorities, I find it stated that horn, steeped for a week in a liquor, the active 
ingredient of which is caustic fixed alkali, becomes so soft that it may be easily moulded into any 
required shape. Horn shavings subjected to the same process become semi-gelatinous, and may be 
pressed in a mould in the form of snuff-boxes and other articles. Horn, however, so treated, becomes 
hard and very brittle, probably in consequence of its laminated structure being obliterated by the 
joint action of the alkali and strong pressure. 

Horn is easily dyed by boiling it in infusions of various colored ingredients, as we see in the horn 
lanterns made in China. 1\ Europe it is chiefly colored of a rich red-brown, to imitate tortoiseshell, for 
combs and inlaid-work. The usual mode of effecting this is to mix together pearlash, quicklime, and 
litharge, with a sufficient quantity of water and a little pounded dragon's blood, and boil them together 
for half an hour. The compound is then to be applied hot on the parts that are required to be colored, 
and is to remain on the surface till the coior has struck ; on those parts where a deeper tinge is required, 
the composition is to be applied a second time. This process is nearly the same as that employed for 
Caving a hrr wn or black color to white hah ; and depends on the combination of the sulphur, (which is 


an essential ingredient in albumen,) with the lead dissolved in the alkali, and thus introduced into the 
eubstance of the horn. The horn which is naturally black is less brittle than that which is so stained. 

Tortoises/tell comes next under consideration. The animal which produces tins beautiful substance 
is a marine tortoise, called the Tesiudo imbricata, or hawk's-bill turtle. 

The usual size of the full-grown animal is about a yard long and three quarters of a yard wide ; its 
covering con-i.-ts of thirteen principal plates, five down the centre of the back, and four on each side, and 
in a tortoise of the above size, the largest, or main-plates, weigh about nine ounces, and measure about 
thirteen by eight inches, and one quarter of an inch thick at the central parts ; but they are thinned 
away at the edges where they overlap, owing to the deposition of the substance of the shell in annual 
layers, each extending beyond the previous one. Very rarely, the shells are three-eighths thick and 
proportionately heavy. Others are very thin, and appear to consist of only one single layer ; this is 
supposed to occur when the animal loses a plate by accident, or that it is stripped and thrown back 
again into the sea whilst alive ; such shells are usually very light-colored and are called " yellow belly." 
There are also twenty-five small pieces of shell which envelop the edge of the aniinal, but these can 
only be applied to very small purposes. 

Some of the tortoiseshell is of very dark-brown tints r. nning into black, and interspersed with light 
gold-colored dashes and marks, these are considered the best ; others are lighter, even to pale red- 
browns, yellow, and white : the last are not valued, the yellow are used for covering the works 01 
musical snuff-boxes, and the light red and brown shells are manufactured into ladies' combs, for expor- 
tation to Spain, where they obtain double the price of those made of the darker colored tortoiseshell: 
The shell of the turtle is also used, but it has not the transparent character of the foregoing ; the colors 
are lighter, less beautifully marked, and it is little valued. 

The treatment of tortoiseshell is essentially the same as that of horn, but on account of its very much 
greater expense, it is economized so far as possible. Before the shells are worked they are often dipped 
in boding water to temper them ; three or four minutes commonly suffice, but they require a longer 
period when they are either thicker or more brittle than usual : excess of boiling spoils the colors of the 
shells, renders them darker, and covers the outside with an opaque white film. Others, flatten and 
temper the shells with hot irons, such as are used by laundresses : the shell is continually dipped in cold 
water to prevent its being scorched; but as a general rule the less tortoiseshell is subjected to heat, or to 
being pulled about, the better, as from its apparent want of grain or fibre, it becomes in consequence 
very brittle. 

Many of the works in tortoiseshell are made, partly by cutting them out of the shell, and partly by 
joining or adhesion, called by the French souder. Thus in the Manuel du Tourneur, the artist is 
directed to form the ring of tortoiseshell for the rebate of a box, by cutting out a long narrow slip 01 
the shell ; the ends are then to be filed with a clean rougli file to thin feather edges, to the extent 01 
three quarters of an inch of their length, the one on the upper and the other on the lower surface, to 
constitute the lap or joint ; the slip is dipped into boding water, and when softened it is bent- into an 
oval form with the intended joint on the flat side, the ends are held in firm and accurate contact with 
the finger and thumb, and the piece is dipped into cold water to make it retain the form. 

A pau- of tongs is required, such as those in Fig. S3, with flat ends measuring about one inch wide 
and three or four long, and that spring open when left to themselves, but fit perfectly close and even, 
when compressed; these are made warm. In 
the mean time the ends of the ring are sprung 33. 

asunder sidewise, to bring the scarfs or parts to r ■ — v. ^— - — " i 

be joined to the inner and outer surfaces respec- I 

tively, that they may be retouched with the file ' ^ " I 

to remove any small portion of grease which may- 
have been accidentally picked up. and the joint 
is restored to its proper position. A piece of 
clean linen is then soaked in clean water, 
squeezed dry witli the fingers, folded in ten to 
twenty thicknesses, to about the size of one and a 
half inch wide, and three or four long ; the ends 

are now folded together, placed on each side the joint, the whole is inserted between the tongs, and 
fixed moderately tight in the jaws of an ordinary vice. The softening and consequent adhesion of the 
shell, will be known by the flexibility of the ring when the loose part is wriggled about with the fingers ; 
the work is either allowed to cool in the vice, or after a time is dipped into cold water. 

The success of the process will depend on tluee different circumstances ; the parts to be joined must 
be entirely free from grease and dirt, on which account the surfaces should not be touched after being 
tiled ; the temperature of the tongs should be just sufficient to color writing-paper of a pale orange 
lint ; and moisture or vapor must be present, apparently to liquefy the gelatine of the tortoiseshell at 
the surfaces of union. 

The ring, when cold, is pressed with the fingers into the circular form or even into an oval in the 
opposite direction, which would cause the ends of the joints to start, if the soldering were imperfectly 
performed ; should this happen, the application of the moistened rag and heated tongs must be repeated 
untfl the result is perfect ; the ring is made circular by warming it in boiling water, and gently forcing 
it on a wooden cone of small angle. 

Another mode, the invention of an amateur, is also described ; the strip of shell is chamfered off at the 
ends and bent round a piece of wood, a compress of linen in six or eight folds is put upon the joint, and 
the whole is tightly bound round with string, and immersed in boiling water for ten tixiutes. The 
contraction of the string, and the expansion of the wood, from being wetted, supply the neeciul pressure, 
»nd the process is said to be quite successful. 

Moulding and soldering tortoiseshell, are also performed under water in various other ways foi 



example, in attaching the back of a large comb, to that piece which is formed into the teeth, the twc 
parts are filfd to correspond, they are surrounded by pieces of linen and inserted between metal 
moulds, connected at their extremities by metal screws and nuts ; the interval between the halves ol 
the mould, being occasionally curved to the sweep required in the comb. Sometimes also the outer 
faces of the mould are curved to the particular form of those combs in which the back is curled round, 
so as to form an angle with the teeth ; the joint when properly done cannot be detected either by the 
want of transparency or polish at the part. 

Considerable ingenuity is shown in turning to economical account the flexibility of tortoiseshell in its 
neated state ; for example, the teeth of the larger description of combs are parted, or cut one out of the 
other with a thin frame-saw, when the shell equal in size to two combs with their teeth interlaced as in 
Fig. 34, is bent like an arch in the direction of the length of the teeth as in Fig. 35. The shell is then 
flattened, the points are separated with 
a narrow chisel or pricker, and the two 
combs are finished whilst flat, with 
coarse single-cut files, and triangular 
scrapers ; and lastly they are warmed, 
and bent on the knee over a wooden 
mould, by means of a strap passed 
round tlie foot, in the manner a shoe- 
maker fixes the shoe-last. Smaller 
combs of horn and tortoiseshell are 
parted whilst flat, by an ingenious 
machine, invented by Mr. Kelly. It lias 
two chisel-formed cutters placed ob- 
liquely, so that every cut produces one 
tooth, the repetition of winch com- 
pletes the formation of the comb. Ivory and boxwood combs cannot be thus parted ; they are cut in 
the old way, one tooth at a time, by various contrivances of double saws, as will be explained. 

In making the frames for eye-glasses and spectacles, the apertures for the glasses were formerly cut 
out to the circular form, with a tool something like a carpenter's centre-bit, or with a crown-saw in the 
lathe ; the disks were in either case preserved, to be used for inlaying in the tops of boxes, and the 
outside of the frame was then shaped witli saws and files. This required a piece of tortoiseshell of the 
entire size of the front of the spectacles, but a piece of a third that width is made to answer for inferior 
spectacles, as the eyes are strained, or pulled. A long narrow piece of the material is cut out, and two 
slits are made in it with a thin saw ; the shell is then warmed, the apertures are pulled open, and 
fashioned upon a taper triblet of the appropriate shape : Figs. 36, 37, and 38, explain this method ; the 
gioove for the edge of the glass is cut with a small circular cutter, or sharp-edged saw, about three- 
eighths or half inch diameter, and the glass is sprung in when the frame is expanded by heat. 

Tortoiseshell is also manufactured into boxes and a variety of moulded works, but the process calls for 
extensive preparations, and is not often followed by the amateur. 

The construction of tortoiseshell boxes requires a copper, with a fireplace beneath ; a trough with cold 
water, and a press and moulds. The former may be compared to the ordinary coining press, or to a 
6trong rectangular frame, usually of wrought-iron, with a screw in the centre of the upper cross-piece ; 
the base of the press is fitted into a square recess in the centre of the bench, fixed so firmly to the Hoc* 
or wall, as to resist the efforts of two or 
three men at the end of a lever five or six 
feet long, whose entire force is sometimes 
required in tightening the mould. For the 
convenience of transferring the heavy press, 
from 'he hole in the bench to the hot or cold 
water, a crane, the centre of which is equally 
distant from the three, is added to the estab- 

The mould required for a round box con- 
sists of a thick wrought-iron ring a a. Fig. 39, 
turned interiorly to the diameter of the box ; 
it stands loosely upon a plate b ; it is ac- 
curately fitted with several pieces, common- 
ly of brass, as e the bottom die, d the top 
die for a plain box, e a plain block for flat 
plates, and /' a die engraved with any par- 
ticular device to be impressed upon the 

In the Manuel du Tourneur the methods 
of making four different kinds of boxes are 
minutely given. Thus in the "Boites a 

feuilles" the best kind, in which the cover | : ~] 

and bottom part are each made out of a 
single leaf of shell; the circular pieces are to ' 

je cut out of the shell as much larger than : . — _^_ 

the size of the box, as the vertical height in 

addition to the diameter ; so that a box of three inches diameter and one inch deep would "equire 

pieces of four and five inches respectively for the cover and bottom 



The round plate of shell is first placed centrally over the edge of the ring, as in Fig. 39 ; it is slightly 
•queezed with the small round-edged block g, and the entire press is then lowered into the boiling water ; 
in one quarter, or half an hour, it is transferred to the bench, and g is pressed entirely down, which bends 
the shell into the shape of a saucer, as at Fig. 40, without cutting or injuring the tortoiseshell after 
which the press is cooled in the water-trough. The same processes are repeated with the die d, which 
has a rebate turned away to the thickness of the shell, and perfects the angle of the box to the section 
Fig. 41, ready for completion in the lathe ; it is however safer to perform each of these processes at twice, 
with two boilings. 

When the shell is insufficiently thick, two pieces are joined together, and should they from the nature 
of the shell be of irregular thickness, the thick and thin parts respectively are placed in contact ; for 
such cases the dies c e, of a larger mould, are used. The piece d is adapted to boxes of various depths, 
or to the tops or bottoms respectively, by slipping loose rings upon it to contract the length of its smaller 

When the box is required to have a device, an engraved die /is substituted in place of c. The 
tools are also used for horn boxes, and for the embossed wooden boxes, but the latter process is mostly 
performed in the dry way, the warmth being supplied by heated plates, put above and below the two 
parts of the mould which are then compressed, and the whole is allowed to cool in the air. 

The Manuel describes the construction of inferior boxes, " Tabatieres de morceaux" in which small 
pieces of tortoiseshell with bevelled edges are carefully fitted together with the file and arranged along 
the bottom and up the sides of the mould ; or else they are first pressed into a flat plate, and made into 
a box as a separate process ; but the joints, from the manner in which they are made, can scarcely ever 
escape observation. 

The " Bo'ttcs de tres-petits morceaux" are made of still smaller fragments, which are often cemented 
on a thin leaf of shell to ensure their better union ; and lastly, the " Boites de drogues" are made of the 
fine dust and filings, which are passed through a sieve, and treated in other respects much in the same 
manner as the foregoing, but these boxes are quite opaque and brittle ; a thin hoop of good tortoiseshell 
is sometimes inserted in the mould, to form the rebate of the box, winch alone is then transparent ; at 
other times, the shavings are mixed with mineral coloring matters, to imitate granite, lapis-lazuli, and 
other stones. 

After the lapse of ten days or a fortnight, it sometimes happens the box shows a tendency to recover 
its primary form, that of a flat plate, and from being cylindrical on the edge, it becomes in a slight de- 
gree conical and larger without. After being again returned to the mould, boiled, and pressed, its figure 
is in general permanent. 

This disposition is turned to useful account in restoring the fitting of a box that may have become 
loose, as by dipping the lower part, or the rebate, into warm water, it will expand and till out the lid, 
but it requires care that it be not overdone. 

The tortoiseshell boxes usually made, are those which are veneered upon a body or fabric of wood, 
for which purpose the plates are scraped and filed to a uniform thickness, and glued on much the same 
as veneers of wood ; generally fine glue is the only cement used, but various compositions are resorted to 
by different manufacturers. To improve the appearance of the shell, and to conceal the glue and wood 
beneath, the back of the veneer is rubbed with a mixture of lampblack, vermilion, green, chrome, or 
white, in fish glue ; the colors are applied over the entire surface, or partially to modify the effect, and 
thus prepared the veneers are glued upon the boxes. 

In tortoiseshell works inlaid with mother-of-pearl and gold or silver plates or wire, the substances to 
be inlaid are first prepared ; and for pearl shell a paper is pasted on a thin piece of pearl, the pattern is 
drawn thereupon, and the small pieces are cut out with a fine buhl-saw : gold and silver plates are some- 
times also thus sawn out. 

A plain mould similar to Fig. 39, but rectangular, and with plain dies, as c and e, is used ; a few 
shavings of tortoiseshell are first placed on the piece c, to make a bed or cushion, then a piece of paper 
to prevent them from adhering to the thin leaf of tortoiseshell, which is next inserted in the mould. The 
small pieces of pearl shell, <fcc. to constitute the pattern, are then carefully arranged in their intended 
positions, and the top plate e is very carefully lowered into the mould above the pieces, so that it may 
not misplace any of them. The mould is then slid into the press, slightly squeezed, and plunged into the 
copper fti an hour, carried to the bench and screwed moderately tight ; the work is now examined to 
see that nothing is misplaced, it is returned to the caldron for a time, and the final squeeze is given by 
the entire force of three men, after which, whilst still under pressure, the whole is plunged into the cold 
water. The tablet is then fit to be smoothed and glued on the wooden box. 

It will be readily conceived, that the force required depends upon the dimensions of the work ; pieces 
of three or four inches square require all the appliances described ; whereas the little ornaments upon 
razors and knives, may be pressed in with much slighter apparatus, such in fact as were previously de- 
scribed as being used in moulding them. In cutlery, a different method is generally resorted to, which 
applies equally well to ivory and pearl shell, substances which cannot be submitted to the softening and 
moulding processes employed for horn and tortoiseshell. 

The cutlery works which are dotted all over with little studs of gold or silver, are drilled from thin 
pattern plates of brass or steel in which the series of holes have been earefuUy made ; the drill or 
" passer" has an enlargement or stop, which, by encountering the surface of the pattern plate, prevents 
the point of the drill from penetrating beyond the assigned depth into the handle ; the holes in the 
ivory or pearl shell are then filled with silver or gold \vire, which is either filed and polished off level 
with the general surface, or allowed to project as little studs. 

For small ornaments they use pattern plates or templets of hardened steel, pierced with the exact 
form. The cutting tool somewhat resembles an ordinary breast-drill eight or ten inches long, and like 
it, is used with the breast-plate and drill-bow ; but the extremity of the tool is cleft, or made in two 
branches, which, left to themselves, spring open to the extent of an inch or more each half of the tool 


has a shoulder or stop, which bears upon the surface of the steel guard-plate, as in the drill, and a 
rectangular cutting part that protrudes tlirough the shield-plate as far as the required depth of the 
recess, and is sharpened both at the end and side, or at the ends only. 

When the elastic tool or " spring-passer" has been compressed so as to enter the guard-plate, ft is 
put in motion, and flounders about in all directions, so far as it can expand, and routs or cuts out the 
shallow recess ; the small ornaments are punched out, fixed by two rivets, and smoothed off; these 
processes are very expeditious, and produce accurate copies of the respective pattern-plates employed. 
The tortoiseshell, when unnecessarily tliick for a single scale for a penknife, is sawn to serve for two ; 
and the colors are brightened up by placing a piece of Dutch leaf beneath the same ; they are finally 
polished on the various wheels used by the cutler. Tortoiseshell has been manufactured into hollow 
walking-sticks, and even bonnets. 

Whalebone may be considered as a kind of horn ; which latter substance it resembles perfectly, both 
in its chemical and principal physical properties ; and is particularly interesting as forming the transi- 
tion from horn to hah. 

It is the substitute for teeth in the Greenland whale, and in the black southern w.nle; but is not 
found hi any of the cetaceous animals that have teeth. 

From the roof of the mouth hang down on each side the tongue about tlu-ee hunched plates 01 
whalebone, all the blades on one side being parallel to each other and at right angles to the jaw-bone. 
The average length of the middle blades is about nine feet, but they have occasionally occurred of the 
length of fourteen or fifteen feet. 

The general color of whalebone is a dusky grayish Black, intermixed with thin stripes or layers of a 
pale color, which are often almost white — very rarely the entire flake is milk-white. 

Tiie preparation of the whalebone for use is very simple. It is boiled in water for several hours, 
by wliich it becomes soft enough to be cut up while hot, in lengths of different dimensions, according 
to the use to which it is to be applied. Whalebone that has been boiled, and has become cold again, is 
harder and of a deeper color than at first ; but the jet-black whalebone has been dyed, and by the 
usual processes it takes very bright and durable colors. 

Whalebone is now principally used for the stretchers for umbrellas, and as a substitute for bristles in 
common brushes ; it is also plaited into whips, and solid pieces of mixed shades are twisted for 
walking-sticks ; but it does not admit of being soldered or joined together like tortoiseshell. Whale- 
bone also furnishes a very neat and durable covering for pocket-telescopes. Narrow pieces of the 
material are grooved or made into ribs, by chawing them like wire through a corresponding aperture 
in a steel plate, after which they are wound round the tube, and " tucked under" the rings at the ex- 
tremities. Broad flat strips of the party-colored whalebone, (the light portions of wliich absorb the 
green dye.) are also used : these are secured by narrow black bands which overlap the two edges, and 
other bauds are wound around the ends also. 

Ivory, the tusk or weapon of defence of the male elephant, and of wliich each animal has two, is 
placed by the chemists intermediately between bone and horn, and its mechanical characters corrobo- 
rate the position. It is generally considered that the male elephant alone possesses tusks, commercially 
known as elephants' teeth, but this appears questionable, as by many the female is reported to have 
tusks likewise, but of smaller size, and some consider the latter produce the small solid tusks called 
" ball ivory," used for making billiard balls. 

Ivory has less gelatine than bone ; but as it leaves the animal in a state fit for use, without the neces- 
sity of removing any of its component parts for its purification, its elasticity and strength are not ins- 
pired by such abstraction. Ivory is not therefore so brittle as bone, neither does it splinter so much 
when broken, but its greater ultimate share of animal matter leaves it more sensible to change of form 
and size. 

The shape of the tusk is highly favorable to its use, as it is in general solid for above half its length, 
and of circular or elliptical section ; it is entirely free from the vessels or pores often met with in bone, 
and although distinctly fibrous, it cannot be torn up in filaments like horn, nor divided into thin flexible 
leaves, as for miniatures, otherwise than by the saw. 

Its substance appears very dense, and without visible pores, as if beautifully cemented by oil or wax ; 
and notwithstanding that it possesses so large a share of lime, it admits of being worked with exquisite 
smoothness, and is altogether devoid of the harsh, meager character of bone. It is in all resper'j the 
most suitable material for ornamental turning, as it is capable of receiving the most delicate lines and 
eutting, and the most slender proportions. 

The general supply of ivory is obtained from the two present varieties of the animal, the Asiatic and 
the African : they are considered by physiologists to be distinct species, and to be unlike the extinct 
animal from wliich the Russians are said to obtain their supply of this substance ; which, although 
described as fossil ivory, does not appear to have undergone the conversion commonly implied by the 
first part of the name, but to be as suitable to ordinary use as the ivory recently procured from the 
living species. An extract from the interesting account of " The Elephant of the Lena" is subjoined as 
a note.* 

* "The Mammoth, or Elephant's bones and tusks, are found throughout Russia, and more particularly in Eastern Siberia 
and the Arctic marshes. The tusks are found in great quantities and are collected tor the sake of profit, being sold to the 
turners in the place of the living ivory of Africa, and the wanner parts of Asia, to which it is not at all inferior." 

"Almost the whole of the ivory-turner's work, made in Russia, is from the Siberian fossil ivory; and sometimes the 
tusks, having hitherto always been found in abundance, are exported from thence, being less in price than the recent. 
Although, for a long series of years, very many thousands have been annually obtained, yet they arc still collected every 
year in great numbers on the banks of tiie larger rivers of the Russian empire, and more particularly those of farther 
Liberia." — The Naturalist's Library, 1830. Mammalia, vol. v., p. 133. 

The Mammoth teeth are but rarely exposed lor sale in this country. I only learn of two ; the one weighed 18G pounds, 
vas 10 feet long, of fine quality, and except the point, which was cracked, was cut into keys for pianofortes ; the other also 
las large, but very much eracktd and useless. Of the latter I have a specimen: the subs'tttnee of the ivory between tbs 


The hippopotamus, or river-horse, supplies the ivory used by the dentist, which is imported from the 
East Indies and Africa ; the animal, in addition to twenty grinders, has twelve front teeth, the whole of 
which agree in substance with ivory, but not in then- size or arrangement. The six in the upper jaw 
are small, and placed perpendicularly ; in the lower jaw of the hippopotamus the two in the centre are 
long, horizontal, and straight, the two next are similar, but shorter ; but the two external semicircular 
teeth are those so highly prized b} T the dentists on account of their superior size, and are those usually 
referred to when the "sea-horse" or hippopotamus tooth is spoken of, although the animal is in reality a 
quadruped inhabiting rivers and marshy places. 

The circular luppopotamus teeth are covered exteriorly with a thick coat of enamel, which entirel? 
resists steel tools, and will even strike tire with that metal ; it is usually removed upon the grindstone'" 
in order to arrive at the beautiful ivory within, which, owing to the peculiarity of its section, is better 
adapted to the construction of artificial teeth than the purposes of turning ; the other teeth are tolera 
bly round, and fit for the lathe. 

The ivory of the hippopotamus is much harder than that of the elephant, and upwards of double the 
value ; in color it is of a purer white, with a slight blue cast, and is almost free from grain The parts 
rejected by the dentists are used for small carved and turned works. 

In texture it seems almost intermediate between the proper ivory and the pearl shell ; as when it is 
turned very thin, it has a slightly ciudled, mottled, or damasked appearance, which is very beautiful ; 
the general substance is quite transparent, but apparently interspersed with groups of opaque fibres, 
like some of the minerals of the chatoyant kind. 

The teeth of the walrus, sometimes called the* sea-cow, which hang perpendicularly from the upper 
jaw, are also used by the dentists ; the outer part, or the true ivory, nearly resembles the above, tut 
the oval centre has more the character of coarse bone ; it is brown, and appears quite distinct. The 
long straight tusks of the sea-unicorn or narwal, which are spirally twisted, also yield ivory ; but they 
are generally preserved as curiosities. These two kinds are principally obtained from the Hudson's 
Bay Company. 

The masticating teeth of some of the large animals are occasionally used as ivory ; those of the 
spermaceti whale are of a flattened oval section, and resemble ivory in substance ; but they are dark- 
colored towards the centre, and surrounded by an oval band of white ivory : like that of the aquatic 
varieties generally, they are not much used. 

The grinders of the elephant are occasionally worked ; but their triple structure of plates of the hard 
enamel, of softer ivory, and of still softer cement, wliich do not unite in a perfect manner, render them 
uneven in texture. Owiug to the hardness of the plates of enamel, the grinders are generally worked 
by the tools of the lapidary ; they are but Uttle used, and when divided into thin plates are disposed to 
separate, from change of atmosphere, the union of their respective parts being somewhat imperfect. 
They are made into small ornaments, knife-handles, boxes, <tc. 

The tusk of the elephant is, however, of far more importance than all these other kinds of ivory, and 
appears to have been extensively used by the Greeks and Romans. Amongst the former, Phidias was 
famous for his statues, thrones, and other works of embellishment, made in ivory combined with gold, 
an art described as the Toreutic. In reference to the construction of ivory statues, Monsieur Quatremere 
de Quincy, in his great work on ancient sculpture, f advances some curious speculations of their having 
been formed upon centres or cores of wood, covered with plates of ivory ; and also that the ancients 
were enabled to procure larger elephants' teeth, or possessed the means of softening and flattening out 
those of ordinary size, from which to obtain the pieces presumed to have been thus employed. 

These questionable suppositions, particularly the last, scarcely seemed called for, as solid blocks oi 
ivory of the sizes commonly met with, would appear to be sufficient for the construction of colossal 
figures, in the mode ingeniously demonstrated by M. de Quincy in his plates 26 to 31. It is much to be 
regretted that none of these statues have descended to our times. 

One of the constituent parts of ivory being annual matter, we should naturally expect it to be less 
durable t 1 an the inorganic materials, in which numerous fine specimens of ancient art still exist in great 
comparative perfection. Ivory appears not to suffer very rapid decay, in the lengthened deposition in the 
frozen earth of Siberia, nor when immersed in water ; but various specimens in the British Jluseum, appa- 
rently less favorably situated, and in contact with the air, exhibit the effect of time, the ivory being decom- 
posed and divided into fla'«a» and pieces which exhibit its lamellar structure in a very satisfactory manner. 

Elephants' teeth differ ojcpMerably in their size, weight, and appearance. The outsides of the African 
teeth run through all the transparent tints of light and deep orange, hazel, and brown, and some are 
almost black. Those from Asia are similar, although generally lighter, and frequently of a kind of 
opaque fawn, or stone-color ; they have seldom the transparent character of the African teeth ; and 
they commonly abound in cracks of inconsiderable depth, from which the others are comparatively free. 

Some teeth are as long as from eight to ten feet, and as heavy as 150, rarely 180 lbs. each tooth ; some- 
times they are only as many inches long, and about one inch in diameter, and of the weight of five or 
fix ounces, and even lighter; the teeth less than from 10 to 14 lbs. are called " scrivelloes." In section, 
the tusks are rarely quite circular, sometimes nearly elliptical, seldom exceeding the proportions of four 
to five, but commonly less exact than either of these forms ; Figs. 43, 44, and 45, are accurately reduced 
from sections of teeth; the largest tusk the author has met with measured eight and a quarter inches 
the longest, and seven inches the shortest diameter of the irregular ovaL 

cracks appears quite of the ordinary character, although the interstices are filled with a dry powder resembling chalk. Botll 
teeth were to/id unto within six inches of the root. 

* The enamel of the hippopotamus is much thicker, but similar to that of the generality of masticating teeth, which is 
found upon analysis to agree very nearly with the hard porcelanous shells. The enamel is sometimes scaled off by driving 
l thin chisel between it and the ivory ; and I learn, the 5:;tr.5 of the blowpipe is likewise frequently used for the purpose 
ti separating it. Several of the other teeth have enamel, but the semicircular tooth by far the most abundantly. 

T Le Jupiter Olympien, ou l'Art de la Sculpture Antique. Paris, ldlo. 


The curvature of the teeth is sometimes as much as the half-circle, as in Fig. 46, and iccasionallv evec 
so little or less than the sixth, as in Fig. 42 ; they are sometimes finely tapered off, especially In th» 
African teeth, at other times their ends are very much worn away, — in rare instances to the extent ot & 
third of their apparent length, and generally more 
so on the one side of the centre than the other. 

Other teeth end very abruptly, as if they had 
been broken and repointed before they left the head 
of the animal, in which they are generally inserted 
for about one-fourth their length. 

The teeth are hollow about half-way up, and a 
6peck, sometimes called the nerve, but in reality 
the apex of the successive hollows, is always visi- 
ble throughout the length of the tusk to its extreme 
end, the tooth being formed by layers deposited 

on a vascular pulp after the manner of teeth gen- 


The inner and outer surfaces of the teeth are in 
general tolerably parallel, and exteriorly they are 
ciuwed in the one direction only, so as to lie nearly 
flat on the ground ; but occasionally they are much 
curved in both directions, as represented in Figs. 
47 and 48 ; the smaller is beautifully formed, and 
resembles in shape a handsome bullock's horn, the 
other is furrowed throughout its length, and ap- 
pears the result of disease or injury. 

The choice of ivory in the tooth is admitted by 
the most experienced to be a very uncertain matter ; of course, for the purposes of turning, a solid cone 
would be the most economical figure, but as that form is not to be met with, we must be satisfied with 

*ie cearest approach that we can find to it, and select the tooth as nearly straight, solid, and round as 
possible, provided the other prognostics are equally favorable. 

The rind should appear smooth and free from cracks, and if the heart should be visible at the tip, 
the more central it is the better ; by the close inspection of the tip, from which the bark is always more 
or less worn away, it may be in general learned whether the tooth is coarse or fine in the grain, trans- 
parent or opaque, but the color of the exterior coat prevents a satisfactory judgment as to the tint or 
complexion of the ivory within. 

After the most careful scrutiny on the outside of the tooth, however, the first cut is always one of a 
little anxious expectation, as the prognostics are far from certain, and before proceeding to describe the 
preparation of ivory, I will say a few words of its internal appearance when exposed by the saw. 

The African ivory, when in the most perfect condition, should appear, when recently cut, of a mellow, 
warm, transparent tint, almost as if soaked in oil, and with very little appearance of grain or fibre ; it is 
then called transparent or green ivory, from association with green timber ; the oil dries up considerably 
by exposure, and leaves the material of a delicate, and generally permanent tint, a few shades darker 
than writing-paper. 

The Asiatic ivory is of a more opaque dead-white character, apparently from containing less oil, and 
»n being opened it more resembles the ultimate character of the African, but it is the more disposed of 
the two to become discolored or yellow. The African ivory is generally closer in texture, harder under 
the tools, and polishes better than the Asiatic, and its compactness also prevents it fro.ii so readily 
absorbing oil, or the coloring matter of stains when intentionally applied. 

The rind is sometimes no more than about one-tenth of an inch in thickness, and nearly of the color 


of the inner ivory, but occasionally it is of double that thickness, dark-colored, and partially stains the 
outer layers. As we do not find all specimens of the most perfect kind, we must be prepared to expect 
others, especially amongst the larger teeth, in which the grain is more apparent, but it generally dies 
away towards the centre of the tooth, the outside being the coarser ; the regularity of the grain some- 
times gives it the appearance of the engine-turning on a watch-case. 

In some teeth, the central part will appear of the transparent character, the outer more nearly white-, 
and the transparent teeth often exhibit, at the solid parts, white opaque patches, which are frequently 
of a long oval form. Amongst the white ivory, the teeth are often found to be marked in rings alter- 
nately light and dark colored ; these are called " ringy or cloudy!' 

In those teeth in which there appears to be a deficiency of the animal oil, the intervals be'.ween the 
fibres occasionally assume the chalky character of bone, and are disposed to crumble under the tools 
unless they are very sharp ; in this they resemble the softer parts of woods when worked with blunt 
tools ; sometimes the ivory is not only coarse but dark or brown, and the two defects not unfrequently 
go together. 

The cracks occasionally penetrate further than they appear to do when viewed from the outside, and 
more rarely a very considerable portion of the tooth is injured by a musket-ball, although the gold and 
silver bullets, said to be used by the Eastern potentates, are exceedingly scarce, or else transmuted into 
iron, of which metal they are commonly found, and less frequently of lead. The ball generally lacerates 
the part very much, and a new deposite of bony matter is made that fills up all the interstices, incrusts 
the hollow, and leaves a dotted mottled mass extending many inches each way from the ball, and which 
completely spoils that part for any ornamental purpose. 

Preparation of loory. — On account of the great value of ivory it requires considerable judgment to 
be employed in its preparation, from three conditions observable in the form of the tusk ; first, its being 
curved in the direction of its length ; secondly, hollow for about half that extent, and gradually taper 
from the solid state to a thin feather edge at the root ; and thirdly, elliptical or irregular in section. 
These three peculiarities give rise to as many separate considerations in cutting up the tooth with the 
requisite economy, as the only waste should be that arising from the passage of the thin blade of the 
saw : even the outside strips of the rind, called spills, are employed for the handles of penknives, and 
many other little objects ; the scraps are burned in retorts for the manufacture of ivory black, employed 
for making ink for copperplate printers, and other uses ; and the clean sawdust and shavings are some- 
times used for making jelly. 

The methods of dividing the tooth either into rectangular pieces, or those of circular figure required 
for turning, are alike in their early stages until the lathe is resorted to : I propose, therefore, to begin 
with the former. The ivory saw, Fig. 49, is stretched in a steel frame to keep it very tense ; the blade 
generally measures from fifteen to thirty inches long, from one and a half to three inches wide, and 
about the fortieth of an inch thick ; the teeth are rather coarse, namely, about five or six to the inch, 
and they are sloped a little forward, that is, between the angle of the common hand-saw tooth and the 
cross-cut saw. The instrument should be very sharp and but slightly set ; it requires to be guided very 
correctly in entering, and with no more pressure than the weight of its own frame, and it is commonly 
lubricated with a little lard, tallow, or other solid fat. 

The cutler generally begins at the hollow, and having fixed that extremity parallel with the vice, with 
the curvature upwards, he saws off that piece which is too thin for his purpose, and then two or three 
parallel pieces to the lengths of some particular works, for which the thickness of the tooth at that part 
is the most suitable ; he will then saw off one very wedge-form piece, and afterwards two or three more 
parallel blocks. 

In setting out the length of every section, he is guided by the gradually increasing thickness of the 
tooth ; having before him the patterns or gages of his various works, he will in all cases employ the 
hollow for the thickest work it will make. As the tooth approaches the solid form, the consideration 
upon this score gradually ceases, and then the blocks are cut off to any required measure, with only a 
general reference to the distribution of the heel, or the excess arising from the curved nature of the tooth, 
the cuts being in general directed, as nearly as may be, to the imaginary centre of curvature. The 
greatest waste occurs in cutting up very long pieces, owing to the difference between the straight Une 
and the curve of the tooth, on which account the blocks are rarely cut more than five or six inches long, 
unless for some specific object. 

In subdividing those blocks wliich are entirely solid, no great difficulty is experienced : in those which 
are nearly soUd, as in Fig. 50, the first step is to cut a central slice just thick enough to avoid the hollow, 
unless the pieces a b are required to have some particular size ; c d would serve for leaves fcr minia- 
tures or veneering, and the remainder would be cut up of any required sizes, as sketched beyond c d 
For square pieces of similar size, the block is cut into parallel slabs ; for bevelled pieces, as the taper 
nandles of knives and razors, the slabs are cut out wedge-form, the thick end of one against the thin 
end of the next, as at e f: these slabs are afterwards divided with parallel or inclined cuts, either with 
the frame or the circular saw. 

In flat works, such as razor and knife handles, the broad surfaces, if cut radially, would show the 
edges of the rings or layers of the ivory ; but cut parallel with the curve or as the tangent, the grain is 



much less observable, and the ivory appears finer. In the keys for pianofortes this is particularlv at 
tended to ; the finest broad keys are always cut upon the flat side of the oval, as at f, those upon the 
long diameter are cut into the narrow pieces called tails, (used between the black keys',) and the inter 
mediate parts are cut obliquely as at g ; this causes much waste. 

For sucli pieces as have large hollows, more management is neces- . 5fl - 

sary, as the thickness and curvatures of the material have to be jointly 
considered. When the hollows are thin, tliey are cut into squares or 
handles as large as the substance will allow ; but ou account of the 
circular section of the tooth, some of the pieces, if not all, must neces- 
sarily be angular or wedge-form ; as regards pieces for the lathe, this 
is of little consequence. 

In all cases the enure division of the block or ring should be deter- 
mined upon, and carefully marked in pencil upon the end of the piece, 
before the saw is used. 

When the tusk is cut up exclusively for turnery-work, the first cut 
is more generally made where the hollow terminates, which spot is 
ascertained by tlu-usting a small cane or a wire up the tooth ; and every 
cut is directed as nearly as possible at right angles to the curve of the 
tusk, or to the centre of the circle, as before described. Unless the 
tooth is very fur from circular, it is usual to prepare the principal 
quantity into cylinders or rings, as large as they will respectively 
hold, aud the diagrams, Figs. 51, 52, and 53, are intended to explain the "~ J i> '■■ 

best mode of centreing the pieces, or placing them in the lathe. 

If, as in preparing an ordinary block of wood, a circle were made at each end, and the work were 
chucked from the centres of the circles, as at o, Fig. 51, the largest cylinder that could be obtained would 

be that represented by the four sides of the dotted rectangle within that figure. Very much less waste 
would result from placing the centres so much nearer to the convex side, as to obtain the cylinder rep- 
resented in Fig. 52, by allowing the waste to be equally divided between the points a, c, aud e. 

It is however more economical, to cut those teeth which are much curved into the shortest blocks, and 
the Fig. 53, which represents the proportions more commonly adopted, shows the small comparative de- 
gree of waste that would occur in a piece of half the length of the others, when centred in the most 
judicious manner. 

The first process in preparing to rough-turn the block, is to fix it slenderly in the lathe between the 
prong chuck and the point of the popit-head, and its position is progressively altered by trifling blows 
upon either end, until when it revolves slowly, and the common rest or support for the tool is applied 
against the most prominent points a, c, and c, respectively, the vacancies or spaces opposite to each, at 
d, b, and/ shall be tolerably equal ; so that, in fact, about a similar quantity may have to be tinned away 
from the parts a, e, and c, for the production of the cylinder, represented by the dotted lines within the 

The centres having been thus found, they should be made a little deeper with a small drill ; and then 
the one end of the block being fixed upon the prong chuck, the opposite extremity, supported by the 
centre, is turned for a short distance slightly conical, ready for fixing in a plain boxwood chuck, or a 
brass chuck lined with wood, to complete the rough preparation, unless indeed it is entirely performed 
upon the prong chuck. 

With the decrease in length, less attention is requisite in the centreing, on account of the interference 
of the curvature of the tooth, and the pieces may be at once rasped to the circular form, and then chucked 
either in a hollow chuck, or else by cement or glue, against a plain flat surface. 

When the blocks of ivory are long and much curved, a thin wedge-form plate may be sometimes sawn 
from the end, in preference to turning the whole into shavings ; the end is turned cylindrieally for a short 
distance, just avoiding to encroach on the lower angle of the block, and as soon as practicable, a parting 
tool is used for cutting a radial notch for the admission of the saw, which may be then employed in re- 
moving a thin taper slice. The process is at any rate scarcely attended with more trouble than turning 
the material into shavings, and thin pieces are retained for a future purpose, such in fact as these repre- 
sented beyond the dotted lines at the ends of the figures. 

The hollow pieces of ivory are treated much in the same manner as those which are solid, and into 
wliich latter condition they are sometimes temporarily changed, by rasping a piece of common wood, such 
as beech, to fit into the hollow, driving it in pretty securely, but so as not to endanger splitting the ivory 
the work is then centred as recently explained, the chuck and centre being in this case received in the 

With the hollow pieces, the process of turning must be repeated on their inner surfaces, for which 
purpose a side cutting tool, with a long handle for a secure grasp, should be used : the too! should be 
held very firnily, so as to withstand the jerking intermittent nature of the cut, until the irregularities are 

For this purpose the sliding-rest is very desirable, as the tool is then held perfectly fast without effort 


on the part of the individual, and if the chucking be correctly done, the greatest possible economy of the 
material is attained ; the hand tools succeed very well on the outer surface, as the rest or support upon 
winch thev are then placed is so close to every point of the exterior surface, that they may be held se- 
curely with less effort, although the sliding-rest is nevertheless desirable there also. 

When the ivory hollow is thin, and far from circular, the material would be turned entirely into 
shavings, in attempting to produce a circular ring ; the circular dotted lines in Figs. 43 and 44, are in- 
tended to explain this. Fig. 43 might be turned into an oval ring ; but it is more usual to cut such 
irregular hollows into small square and round pieces, as explained. 

When thin rings or short tubes are required, they are frequently cut one out of the other in the lathe, 
in preference to wasting the material in shavings ; this is done with the parting tool, as in Fig. 54 ; an 
incision being made of uniform diameter from each end, and continued parallel with the axis, until the 

two cuts meet in the centre ; very short pieces may be thus divided from the one end only. When the 
rings are large and thin, it is desirable to plug them at one or both ends, with a thin piece of dry wood, 
turned as a plug to fill the diameter, and prevent the ivory from becoming oval in the course oi 

Fig. 55 explains the mode of preparing such an object as a snuff-box out of a solid block ; that is, 
with the ordinary parting tool entered from the front, and the inside parting tool entered from within ; 
the incisions of which meet and remove a series of rings. The dotted lines represent the paths of the 
respective tools, the shaded parts the ring obtained, and the black lines the tools themselves. An 
aperture must necessarily be made in the centre, of a diameter equal to the extreme width of the tool ; 
but after the removal of the first, or central ring, a tool of considerably larger size may be used to ex- 
tract a much wider ring ; and a little tallow or oil applied to the parting tools, will, in a great measure, 
prevent the shavings of the ivory from sticking to them and impeding their progress. 

Ivory requires a similar drying, or seasoning, to tliat recommended for wood ; as when the pieces cut 
out of the tooth are too suddenly exposed to hot dry air, they crack and warp nearly after the same 
manner as wood, and the risk is the greater the larger the pieces ; and on this account ornaments turned 
out of ivory or wood, especially those composed of many parts, should not be placed upon those 
chimney-pieces which, from their size, are so close to the fire as to become heated thereby in auy sensi- 
ble manner. 

Notwithstanding the difference between the component parts of wood and ivory, and that the latter 
does not absorb water in any material degree, it is subject to all the changes of size and figure expert 
enced by the woods, and in one respect it exceeds them, as ivory alters in length as well as width 
whereas from the former change wood is comparatively free. 

The change, however, is very much less in the direction of the length than the width ; this is particu 
larly experienced in billiard-balls, which soon exhibit a difference in the two diameters, if the air of the 
apartment in which they are used differ materially from that in which the ivory had been previously 
kept. The balls are usually roughly turned to the sphere for some months before they are used, to 
allow the material to become thoroughly dry before being turned truly spherical ; and in some of tin. 
clubs they even take the precaution of keeping the rough balls in their own billiard-room for a period, 
to expose them to the identical atmosphere in which they will be used. 

It may be asked, what means there are of bleaching ivory which has become discolored ; the author 
regrets to add that he is unacquainted with any of value. It is recommended in various popular works- 
to scrub the ivory with Trent sand and water, and similar gritty materials ; but these would only pro- 
duce a sensible effect, by the removal of the external surface of the material, which would be fatal to 
objects delicately carved by hand, or with revolving cutting instruments applied to the lathe. 

Perhaps it may be truly advanced, that ivoiy suffers the least change of color when it is exposed to 
the light, and closely covered with a glass shade. It assumes its most nearly white condition when the 
oil, with which it is naturally combined, is recently evaporated ; and it is the custom in some thin works, 
such as the keys of pianofortes, to hasten this period, by placing them for a few hours in an oven heated 
in a very moderate degree, although the more immediate object is to cause the pieces to shrink before 
rhey are glued upon the wooden bodies of the keys. Some persons boil the transparent ivory in pearl- 
ash and water to whiten it ; this appears to act by the superficial extraction of the oily matter as in 
bone, although it is very much better not to resort to the practice, which is principally employed to 
renler that ivory which is partly opaque and partly transparent, of more nearly uniform appearance. 

It is imagined by some that ivory may be softened so as to admit of being moulded like horn oi. 
lortoiseshell : its different analysis contradicts this expectation ; thick pieces suffer no change in boiling 
•vater, thin pieces become a little more flexible, and thin shavings give off their jelly, which substance 
is occasionally prepared from them. Truly, the caustic alkali will act upon ivory as well as upmi most 



animal substances, yet it only does so by decomposing it ; ivory, when exposed to the alkalies, first be 
comes unctuous or saponaceous on its outer surface, then soft, if in thin plates, and it may be ultimately 
dissolved, provided the alkali be concentrated ; but it does not in any such case resume its first con 

Ivory is not in all cases used in solid pieces, to which the foregoing remarks principally apply ; but 
is frequently cut into thin leaves and glued upon fabrics of wood, for the manufacture of small orna- 
mental boxes, and works of various kinds, after the manner of the veneers of wood, or the plates of 
tortoiseshell ; it is also used in buhl works, combined with ebony. Such thin plates are usually cut out 
of the solid block, parallel with the axis of the tooth, as at c </, in Fig. 50, with a fine feather-edge 
veneer saw; but the mode introduced in Russia for cutting veneers spirally from a cylindrical block of 
wood, with a knife of equal length, (as if the veneer were uncoiled like a piece of silk or cloth from a 
roller,) has been latterly applied to the preparation of ivory into similar veneers, converting the cylinder 
of ivory into one ribbon, probably by the action of a reciprocating-saw.* 

The modes pursued in these veneered works are analogous to those to be described in the 
article in reference to woods ; it is, therefore, only necessary to a^ d a few words on the white-fish 
glue, or " Diamond cement," as it is sometimes called, which is very often used for ivory-work, both in 
attaching ivory to ivory, and ivory to wood. 

This cement is made of isinglass, (which is prepared from the sound, or swimming-bladder of the 
sturgeon,) dissolved in diluted spirits of wine, or more usually in common gin. The two are mixed in a 
bottle loosely corked, and gently simmered in a vessel containing boiling water : in about an hour the 
isinglass will be dissolved and ready for use ; when cold, it should appear as an opaque, milk-white, 
hard jelly ; it is remelted by immersion in warm water, but the cork should be at the time loosened, 
and it may be necessary, after a time, to add a little spirit to replace that lost by evaporation. Isin- 
glass, dissolved in water alone, soon decomposes. 

Factitious ivory and tortoiseshell have been prepared in France in thin plates or veneers. 

Having adverted to many animal substances suitable to the mechanical arts, obtained from various 
inhabitants of the land and water, let me, in conclusion, mention some that are obtained from the 
feathered tribes — namely, the eggs of birds ; winch, although of limi ted application in the arts of em- 
bellishment, have at all ages served as models or standards of beautiful form. 

They may be made to answer in a very perfect manner for the bodies of vases, the feet and upper 
parts of which are turned out of wood or ivory ; for this purpose the egg-shells have been commonly 
used in then- entire state, a hole having been made at the top and bottom for the extraction of their 
contents, and the attachment of the remaining parts. I have now the pleasure to bring before the 
reader a method of cutting the shells of the eggs of our various domestic fowls, and other birds, for the 
formation of vases with detached covers. 

In the accompanying drawing is represented the nose of a lathe, with an egg chucked ready for cut- 
ting. Fig. 56 is the section of a chuck for holding the eggs to prepare them for the chuck represented 
in Fig. 57. 

Fig. 56 is what is generally termed a spring chuck, 56. 

and is made by rolling stout paper, thoroughly moist- 
ened with glue, upon a metal or hard- wood cylinder, 
the surface of which has been greased to prevent 
the paper adhering to it, and upon which it must re- 
main until perfectly dry, when it may be removed, 
and cut or turned in the lathe as occasion may re- 

This sort of chuck is very light, easily made, and 
well adapted for the brittle material it is intended to 
hold. Before fixing the egg in it, the inner surface 
Bhould be rubbed with some adhesive substance, 
(common diachylon answers exceedingly well ;) when 
this is done, the egg should be carefully placed in 
the chuck, the lathe being slowly kept in motion 
by one hand, whilst with the other the operator 
must adjust its position, until he observes that it runs 
perfectly true ; then, with a sharp-pointed tool he 
must mark the centre, and drill a hole sufficiently 
large for the wire in the chuck, Fig. 57, to pass freely 

When this is done, the egg must be reversed, and 
the same operation repeated on the opposite end ; <5 

its contents must then be removed by blowing care- 
fully through it : it is now ready for cutting, for which purpose it must be fixed in the chuck shown in 
Fig. 57, which is made as follows : 

_ A is a chuck of box, or other hard wood, having a recess turned in it at a i, into which is fitted a 
piece of cork, as a soft substance for the egg to rest against B is a small cup of wood, with a piece of 
cork fitted into it, serving the same purpose as that in A. A piece of brass, d, is to be firmly screwed 
into the chuck A, and into that a steel wire, screwed en the outer end. 

* Monsieur H. Pape, of Paris, pianoforte manufacturer, has taken out patents for this method of cutting tvory spirally 
into sheets. A specimen, 17 inches by 3S inches, and about one-thirtieth of an inch thick, glued upon a board, may be 
Been at the Polytechnic Exhibition in KegeM-street, and M. Pape advertises to supply sheets as large as 30 by 150 inches. 
He has veneered a pianoforte entirely with ivory. 



ANIMAL STRENGTH. Of all the first movers of machinery, the force derived from the strength 
of man or other animals, was first used ; and at present, in a multitude of cases is still the most conve- 
nient. As horses were formerly employed for the same purposes as water-wheels, wind-mills, and 
steam-engines now are, it has become usual to calculate the effect of these machines as equivalent to so 
many horses ; and animal strength becomes thus a sort of measure of mechanical force. 

When an animal is at rest, and exerts its strength against any obstacle, then the force of the animal 
is greatest, or the animal when standing still, will support the greatest load. If the animal begins to 
move, then it cannot support so great a load, because a part of its strength must be employed to effect 
the motion, and the greater the speed with which the animal moves, the less will be the foi'ce exerted on 
the obstacle, or the less will be the load which it is able to carry, for the greater will be the portion of 
its strength directed to the movement of its own body; and there will be a speed with which the animal 
can move and carry no load, but where the whole of its strength is employed in keeping up its velocity. 

It is clear that in the first and last of these cases, the useful effect of the animal is nothing, in a me- 
chanical point of view. There must however be a certain relation between the load and speed of the 
animal, in which the useful effect is a maximum. It has been found that the mechanical effect of any 
animal at work during a given time, is greatest when the animal moves with one-third of the greatest 
velocity with which it can move unloaded, and the load which it bears is four-ninths of that which it 
can only move. The mechanical effect of any animal depends upon the load which it carries, and the 
speed with which it moves, conjointly; and thus to find the mechanical effect of an animal, we have 
only to multiply the load by the speed ; hence the mechanical effect of a man carrying a load of GO lbs., 
and moving at the rate of 3 feet in the second, is 3 x 60=180. "When a man goes up a stair unloaded, 
his quantity of action is the greatest possible, but his useful effect is nothing. When he is loaded his 
quantity of action is less, but his useful effect is more than formerly. In fact, it was found by Coulomb, 
that the greatest useful effect was produced when the weight which the man bore was 0-756, or f of his 
weight ; or assuming the weight of the man to be 150 lbs., the load would be 112A lbs. 

When a man travels unloaded on a level road for several days, he can hardly walk more than 31 miles 
a day, which gives for the quantity of a man's action hi this way 7700 lbs., carried 1091 yards. The 
quantity of action of a man walking up a stair, is to that when he walks on a level road, as 1 to 17. 

The following table exhibits the average amount of mechanical effect produced by men and animal3 
in different applications ; the animal working with a mean velocity and effort during an average day's 
work, thereby producing the maximum effect. 

Nature of the work. 

Effort ex- 


Effect per 













































iMocbjin ea! effect 

Man working at a lever, as in pumping, 
'■ at a crank. Length of crank 10 to 18 inches; 
height of axis of shaft, 36 to 39 inches, . 

" tread-mil! at level of axis 

11 " " at angle of 24 D from the vertical, 

" at a vertical capstan, 

Horse at a whim gin not less than 20 feet radius, 
Draught by traces, according to Gerstner: "Weight 

Man, 150 

Horse, 600 

Mule, 500 






Desaguliers and Sweaton state the strength of a horse to be equivalent to five men ; French writers to 
seven ; Dr. Gregory to six. It is however to be remarked in comparing the strength of a horse with 
that of a man, that the most advantageous way to apply the strength of the one, is the least advantage- 
ous to the other. The worst way to apply the strength of the horse, is to make him carry a weight up 
a steep hill, while the structure of man fits him very well for that purpose. 

'When a horse is employed in a gin, as is often practised in grinding and threshing mills, it is desirable 
to give as great a diameter as possible to the circle in which the animal walks. In practice it may be 
stated, that the diameter of the gin walk ought not to be less than 25 or 30 feet. 

According to Desaguliers, a horse's power is equivalent to 41000 lbs. raised one foot high in one 
minute of time. During 8 hours, according to Watt, 33000 lbs. 

ANNEALING. Glass, cast iron, and steel, together with other substances, when heated, and then 
allowed suddenly to cool, become hard and brittle, a circumstance which often renders them unfit for 
the purposes for which they are intended. To obviate this inconvenience, these bodies are, when heat- 
ed, allowed gradually to cool, and this process is called annealing. Glass vessels after having been 
blown, are placed in an oven called the leer, which is situated immediately over the great furnace, where 
they are allowed to remain gradually cooling for a greater or less time according to their thickness. 
The best way of annealing steel, is to render it red hot in a charcoal fire, taking care that the metal be 
completely covered, and then allowing the fire to go gradually out of its own accord. Cast iron cannot 
be managed in this way, as, being bulky, the expense of charcoal would be enormous ; it is therefore 
usual to employ turf or cinders, the process being otherwise conducted the same way as with steel. In 
annealing east iron, it is not desirable that the metal should be brought to any more than a red heat, 
as otherwise the smaller pieces, and thin bars might not only bend, but even melt. In annealing cast 
iron when the pieces are numerous, and the fire too small, or, when it is suspected that the heat of the fire 
when left to itself may become too great, the pieces are, when red hot, buried in dry savv dust, and in 
that state allowed to anneal. One great advantage of annealing cast iron, is, that if it is afterwards sub- 
jected to a partial heating, it is less liable to warp than it would otherwise be. The character of cast 



iron is not in any way altered by annealing, except that it is rendered more malleable. Cast iron when 
employed in cutlery, is commonly bedded in some poor iron ore, or some substances which give out ox- 
ygen, and kept in a state little short of fusion for twenty-four hours ; it is then found to be in a state 
not unfit for some kinds of edge tools and nails, and to retain a considerable portion of that malleabil- 
ity imparted to it by annealing. It is remarkable, that annealing makes copper hard and brittle, and 
that sudden cooling has the contrary effect. See Iron. 

ANNIHILATOR. See Fire Annihilatok. 


ANTIMONY, a metal usually found in a crude state combined with sulphur, of a bluish-white color 
crystalline texture, brittle and easily pulverized. 

Manufacture. — The smelting of this metal is very simple. The crude ore is picked by hand ; the 
pieces are broken to the size of an egg; and by means of a hand hammer, the gangue, such as quartz,, or carbonate of lime is removed. These pieces may be heated in an earthenware pot, in the 
bottom of which is a small aperture. The sulphuret of this metal, melting at a very low heat, will 
flow out from the gangue, and may be gathered in another pot set below. The operation used to be 
performed in this manner; but as it is expensive, the ore is at present melted in a reverberatory furnace, 
the hearth of which is very concave, and formed of sand. In the centre of the hearth, at its deepest 
part, there is a tap-hole which communicates with one of the long sides of the furnace. The ore on be- 
ing sorted, is spread over the hearth of the furnace, and is there melted. The tap-hole is stopped by 
dense coal-dust, while the reduction is going on. 

Uses of A ntimony.— Besides its employment in medicine, it is much used for forming alloys ; of these 
type-metal, and anti-friction-metal — which is type-metal with the addition of copper — are those most 
used. Eijrhty parts of lead and twenty of antimony form type metal ; to this ommonly five or six 
parts of bismuth are added. Tin SO parts, antimony 20, is music metal; it is also composed of 62. S 
tin, 8 antimony, 26 copper, and 3.2 iron. Plate pewter also contains from 5 to 7 per cent, of antimony ; 
89 tin, 7 antimony. 2 copper, 2 iron, is one of these compositions. Britannia metal contains frequently 
an equal amount of antimony. Queen's metal is 75 tin, 8 antimony, 8 bismuth, and 9 lead. Antimony 
and tin, melted together in equal parts, form a moderately hard, brittle, but very brilliant alloy, wdiich 
is not soon tarnished, and is frequently employed for small speculums in telescopes. Crude antimony is 
employed for purifying gold. 

ANVIL. See Forging. 

APPLE-TREE. See Woods, varieties of. 

APRICOT-TREE. See Woods, varieties of. 

APS. See Woods, varieties of. 

AQUEDUCT, a conduit for water : as an illustration of an Aqueduct for the conveyance of a canal 
across a river we instance the Aqueduct Wire Suspension, over the Alleghany River at Pittsburg, con- 
structed under the superintendence of John A. Roebling, at the western termination of the Pennsylvania 
Canal. This work consists of 7 spans, of 160 feet each, from ceutre to ceutre of pier. The trunk is 
of wood, and 1140 feet long, 14 feet wide at bottom, 16i feet on top, the sides Si feet deep. These, as 
well as the bottom, are composed of a double course of 2i inch white-pine plank laid diagonally, the 
two courses crossing each other at right angles. The bottom of the trunk rests upon transverse beams, 
arranged in pairs, four feet apart ; between these, the posts which support the sides of the truuk are 
let in with dovetailed tenons, secured by bolts. The outside posts which support the sidewalk and tow- 
path, incline outwards, and are connected with the beams in a similar manner. Each trunk post is held 
by two braces, 24- x 10 inches, and connected with the outside posts by a double joint of 2£ x 10. The 
truuk-posts are 7 inches square on top, aud 7 x 14 at the heel; the transverse beams are 27 feet long 

and 16x6 inches ; the space between two adjoining is 4 inches. It will he observed that all parts of 
.he framing are double with the exception of the posts, so as to admit the suspension rods. Each pail 
of beams is supported on each side of the trunk by a double suspension rod of 1-Jth. inch round iron, 
bent in the shape of a stirrup, and mounted on a small cast iron saddle, which rests on the cable. These 
saddles are connected on top of the cables, by links, which diminish in size from the pier towards the 
centre. The sides of the trunk set solid against the bodies of masonry, which are erected on each pier 
ai.d abutment as bases for the pyramids which support the cables. These pyramids which are con- 


rtructed of 3 blocks of a durable, coarse, bard grained sand-stone, rise 5 feet above tbe level of the 
sidewalk and towpath, and measure 3x5 feet on top, and 4x6^ feet at base. Tbe ample width of the 
tow and foot path is therefore contracted on every pier; but this arrangement proves no inconvenience, 
and was necessary for tbe suspension of tbe cables next to the trunk. 

The caps which cover the saddles and cables on the pyramids rise 3 feet above the inside or trunk 
railing, and would obstruct the free passage of the tow-line ; but this is obviated by an iron rod which 
passes over the top of the cap and forms a gradual slope down to the railing on each side of the pyramid. 
The wire cables, which are the main support of the structure, are suspended next to the trunk, one 
on each side ; each of these two cables is exactly 7 inches in diameter, perfectly solid and compact, and 
constructed in one piece from shore to shore, 1175 feet long; it is composed of 1,900 wires of jth inch 
thickness, which are laid parallel to each other. Great care has been taken to insure an equal tension 
of the wires. Oxidation is guarded against by a varnish applied to each wire separately ; their preser- 
vation, however, is insured for certain by a close, compact, and continuous wrapping, made of annealed 
wire, and laid on by machinery in the most perfect manner. The extremities of the cables do not 
extend heloio ground, but connect with anchor chains, which in a curved line, pass through lirge masses 
of masonry, the last links occupying a vertical position : the chains below ground are imbedded and 
completely surrounded by cement. Where the cables rest on the saddles, their size is increased at two 
points by introducing short wires, and thus forming swells, which fit into corresponding recesses of the 
casting. Between these swells the cable is forcibly pressed down by three sets of strong iron wedges, 
driven through openings which are cast in the side of the saddle. 

AQUEDUCTS, for the water supply of cities. The Aqueduct of Spoleto, constructed in 741 by The- 
odoric, king of the Goths, to communicate with the town of Spoleto, is situated on tbe summit of a moun- 
tain. It is one of the handsomest structures of the kind, and remains entire to the present day. In 
crossing the river Be La Morgia, the channel-way is supported upon two tiers of Gothic arches, the 
lower containing ten graud arches, and the latter thirty. The length of this arcade is S00 feet, the 
breadth 4-4, and the height 120. The Aqueduct of Caserta, built in 1753 by Charles III. of Naples, is 
also an expensive and gigantic structure ; one of its arcades consisting of three tiers of arches, 172-4 
feet long, and 190 feet in height. In France, that which conducts the waters of St. Clements, and Dn 
Boulidou to Montpelier, is perhaps the most beautiful. It was built under the superintendence of M. 
Pitot, and required thirteen years for its completion. The principal arcade is 90 feet high, and consists 
of two tiers — the lowest containing 90, and the upper 210 arches. That of Arcueil deserves next to be 
noticed. It was originally built by tbe Emperor Julian, a.d. 360, to bring water to Paris, and supplied 
the palace and hot-baths, but was destroyed by the Normans. After it had been in disuse for 800 years, 
it was rebuilt in 1634 ; again repaired in 1777; and fresh sums have lately been devoted to the same 
purpose by tbe city of Paris. The arcade over the valley of Arcueil consists of 25 arches, is 72 feet 
high, and 1,200 feet long. The Aqueduct of Lisbon, completed in 1738, is about three leagues in 
length, and in some part of its course has been excavated through hills ; but near the city it is carried 
over a deep valley, for a length of 2,400 feet, by several bold arches, the largest of which has a height 
of 250 feet, and a span of 115 feet. 

AQUEDUCT, CKOTON, for the supply of the City of New York. The Croton River rises in Put- 
nam County in three springs, whose rivulets unite near Owentown ; its water is increased by tbe surplus 
of several lakes, which collect the water of the country by different small streams above ami under 
ground. The route for the conduit canal commences near the village of Mechaniosville, runs along the 
left shore (looking downward) of the Croton, and the left shore of the Hudson Paver, and crosses Har- 
lem River by High Bridge to the city. The execution of the work was intrusted to Mr. John B. Jems, 
a practical and experienced engineer, who had been previously engaged in the execution of state canals. 

The line of the aqueduct was portioned off into 4 divisions of 10 to 11 miles extent each, by Mr. Jervia 
the chief engineer. 1st division contained the dam, and stretched some distance below Sing-Sing, the 2d 
to Cook's run, the 3d to Fordham Church, and the 4th to the distributing reservoir. The whole amount 
of the work was given out in 99 Sections, one after the other, under contract. 

The Croton Dam. — At the above-mentioned point, the dam was erected in order to raise 
the water, and to form the Croton lake. Fig. 61 shows the profile of the river. At first a length 
of only 90 feet was given for the dam B, and this part was erected after tbe profile of Fig. 59, with a con- 
struction similar to that of Fig. 62, extending then only from a to 6, Fig. 61, occasion for which was given 
by the rock lying here affording a good foundation : the remainder of the river profile to d, was to be 
filled with an earth embankment. A considerable freshet, however, carried away this embankment when 
partly completed, and it was resolved to extend the stone dam 180 feet further, to c. For the erection 
of this part, A, Figs. 61 and 62, the bottom of the river was cleared from mud and boulders, and the piers 
C and D, of 12 inch hemlock timber, successively built up ; the walls were connected together by ties, and 
filled with stone closely packed in ; the top was covered with six-inch plank of white pine, and treenailed : 
npon this planking, the timber-piers F and G were erected, but only F covered with plank. While erect- 
ing those piers, the space E was filled with concrete, and the piers near tbe top connected with ties. 
Both these piers, together with their filling of concrete, being the armature of the dam, served at the 
same time for a coffer-dam against the water above. Against G, another timber pier was in like man- 
ner constructed, with but one timber wall ; in place of the other, anchors of round timber were laid in, 
and with the ties joggled together. The timber of these piers is of hemlock, 12 inches by 12. the ties of 
white oak, 7 inches thick at the smaller end, framed with single dovetails 4 inches thick, Fig. 65, and 
fastened with one-inch treenails, which are placed 10 feet from centre to centre. The pier-timbers, Figs. 63 
aud 66, are treenailed 30 inches deep, with 2-inch treenails of white oak. These nails are sometimes put 
nearer together, and the ties likewise. The planking is of white pine. When the timber piers had 
reached a certain height, the piers K K, of four compartments, were put down, two of which, tbe nearest to 
low water, were packed out with stone ; the two others were filled with concrete, and formed the coffer- 
dam against the water below the dam. The courses were of 12 by 12 inch hemlock ; the ties of oak, 9 



Boali.— One inch=20 feet. One inch=8 feet. 


inches at the smaller eud, and 6 feet apart from centre to centre ; the treenails of the pquared timber tha 
Bame. The uppermost of them are made of elm and white oak, treenailed every 3 feet, 30 inches deep, 
2J inches in diameter. The upper ties, Figs. 6+ and 66, are of elm 12 inches square ; to this course of ties 
a bed timber of white elm is joggled and secured by iron screw-bolts, Fig. 6G. Across these bed timbers 
or caps, an apron-planking of 6-inch elm is fastened by lj-inch locust (robinia pseudo acacia) tree- 
nails of 1 3 inches in length. Against the rear of this timber pier the one marked L was erected ; 
against the back-water only, it has a regular timber wall, Fig. 63 : the ties are secured by anchors. A 
part of the apron planking of this pier is laid horizontally in connection with the apron of the pier K ; the 
remainder is put three feet lower, Fig. 62. After the pit had been laid dry by pumps, the ground and 
the space at f were filled in with concrete and levelled off. On this bed the body of the dam was by 
degrees erected of hydraulic stone-masomy, according to the bond, Fig. 67, and the courses of face-stone 
for the weir laid down. Tlu's face-work is of granite, cut with such closeness as to allow the stone to be 
laid with a joint not exceeding three-sixteenths of an inch. The masonry is laid in horizontal courses 
to 3 feet from the extrados of the face-work, where it is in courses corresponding with the radii. In 
front of the Up of dam below the head-water, a fore-embankment, Figs. 59, 60, and 62, was formed of 
earth, and its upper part secured with a dry stone-pavement 2 feet thick. 

In the part of the dam first erected, B, Fig. 61, at 6, and Fig. 60 at b, a waste-weir is constructed, in 
order to draw off the water of the lake from a greater depth ; it consists of a well with culverts having 
two sets of gates, all of which are protected with a small stone-house, Figs. 60 and 61, at b ; which can 
be reached by the bridge B, Figs. 59 and 61. 

At a distance of 300 feet from the lip, a secondary dam, Figs. 59 and 60, is constructed ; it is erected 
of round timber, filled up with thy stone. The object of this secondary dam is to divide the head of 
water, and by means of the water-basin formed by it, to break the body of water running over the weir, 
and to keep the wood-work of the timber-piers K and L, under water. Near the left shore a waste- 
weir is constructed in this dam, in order to let off the water from the basin when required. 

By the construction of the Croton dam the water was raised 40 feet, whereby the river passed its 
shores and formed the Croton lake : this is the collecting-reservoir of the aqueduct, containing in it, at 
a depth of 6 feet, 600000000 gallons of disposable water, above the level that would allow the aque- 
duct to discharge S5000000 gallons per day; — sufficient for 1750000 inhabitants, at the rate of 20 gal- 
lons daily per head, including manufactories, shipping, watering streets, gardening, baths, ttc. The flow 
of the Croton is about 27000000 gallons in 24 hours, at the lowest stages, which continues, with mode- 
rate rains, from two to three months in the year. "Whenever the wants of the city may require the 
above-mentioned amount, it will be necessary to draw from those 500000000, daily, SOOtlOOO to make 
up these 35000000. The amount of the reservoir would thus afford a supply for 62 j days. Never has 
the water in summer been so low. The supply of the Croton from its daily flow, aided by the reser- 
voir, may therefore be taken, with great confidence, at 35000000 gallons ; and when the day arrives 
that will require a larger quantity, it may be obtained by constructing other reservoirs further up the 
6tream, where there are abundant facilities for such purposes. 

Profile of the Aqueduct. — At the first consideration of the adopted plan, to conduct water from 
the Croton river, an open trapezoidal canal was proposed. The flow of the water over earth and rock 
might, however, impregnate the conduit-water therewith ; — and as a good deal might sink into the bot- 
tom, it became necessary to make the bed waterproof ; to do this with tight earth seemed insufficient, 
though brick with concrete under it might answer. The open canal remained, however, exposed to the 
sun and to evaporation, as well as to the wading of cattle, to bathing, and to being filled up with earth, 
boulders, and snow washed in ; and might, in fine, freeze out in winter ; it became necessary, therefore, 
to cover it, as had been found indispensable already, at deep-cuts, and in the vicinity of villages. A 
protection with a kind of wooden roof was some time under discussion, (seeming economical,) having 
the deep-cuts and tunnels arched. This mode of roofing, however, did not seem impenetrable to frost 
and heat ; it was resolved, at last, to arch the whole, notwithstanding the great expense. 

The artificial Croton lake stretches more than 5 miles on the line of the original bed of the river, 
which makes the total length of the whole work amount to 50 miles. 

The regulation of all the measurements in heights and depths was taken from a grade-line or planum 
which is 7 inches below the intrados of the inverted arch at the bed of the aqueduct, being the base- 
line or basis-surface of the aqueduct-masonry, in cuttings into the natural ground. 

Length, Inclination, and Grade. — The fall of the aqueduct on the continent is 0.021 per hundred, 
or 1.1088 feet per mile. The roofing-arch follows accurately this inclination, except a distance of 2276 
feet next the dam, which runs horizontally at the height of the lip of the dam. At the entrance, 2.93 fe»t 
were added to the height, which brought this to 11 feet 5 inches in the clear, (Fig. 62.) From the 
lower intrados the inclination is 0.0113 per 100, or 0.59664 feet per mile, at a distance of 4.949 miles, 
where it meets the general inclination and the profile of the aqueduct, as shown in Figs. 68, 69, 70 
This arrangement, which, in a certain way, can be considered as an extension of the lake, renders it pos- 
sible to draw water from a depth of 1 1 feet 5 inches, and to cany it, under influence of its head, with 
less fall, over this distance. At the level of the Up of the Croton dam the aqueduct has still a capacity 
to draw off 35000000 gallons every 24 hours, as experiment has shown. 



Table of Lengths and Inclinations. 

From the dam to the meeting of the general inclination... 

From here to Harlem river the general inclination 0.021 
per 100 or 1.1088 feet per mile of 5280 feet 

At the aqueduct-bridge of Harlem river to the general 
inclination 2 feet are added, the water being earned 
over in pipes by a siphon of 12 feet 

To Manhattan valley the general inclination of 1.10S8 feet 
per mile 

Across Manhattan valley the water passes in a siphon of 
109 feet head, for that reason 3 feet are added to the 
general inclination 

From here to the receiving-reservoir 9 inches per mile .... 

From the influence-gate of this reservoir to its effluence- 

To the distributing-reservoir the water is carried in a si- 
phon by pipes; for the entire distance 


These 47.9069 feet form the fall at the bottom of the aque- 
duct; at the head this bottom is 11.4633 F. 

below the surface of the hike, but only 8.2000 " 

at the discharge in the receiving-reservoir 

whieh gives 3.2633 " 

difference, added to the fall at bottom ; this makes the 
entire fall, or the accurate difference between the surface 
of the Croton lake and that of the distributing-reservoir 

When to this extension of the aqueduct that of the large 

mains is added, which is about 

we have the following as the entire length of aqueduct 
froin its head to the distribution of the water, viz. : — 

Distances in 
Miles. | Feet. 

2?. 9316 















Oonstp.uctiox op Aqceduct-caxal.— "Where the masonry of the aqueduct is cut in level ground or side- 
hills, a course of concrete 3 inches high is laid under the whole extent of masonry ; under the 
extrados of the inverted arch, as high as the shape of the extrados required. Where water-veins 
were met, and in loose ground, or where the depressed ground made foundation walls necessary, the 
concrete bedding was put 12 inches high as broad as the clear width of the aqueduct; but under the 
side walls only 6 inches. In both cases each of the side walls was carried up 13 inches high perpen- 
dicularly, by which the spring-line of the inverted arch was reached ; after this the inverted arch was 
turned J a brick 4 inches thick, the stone part of the side walls carried up 4 feet high, and on both 
sides plastered | inch thick with hydraulic mortar. When these walls had set, the inner facing, i a 
brick 4 inches thick, was carried up ; at last the roofing-arch, 1 brick 8 inches thick ; then the span- 
dril-backing, over which and the upper part of the extrados, plaster of § inch thickness was laid on and 
smoothed oft with the trowel. Where suitable stone was to be had near, the side walls could be car- 
ried up; also the roofing-arch, which in this case was turned 12 inches thick; this, however, has been 
carried into execution in but few instances. The courses of masonry were levelled off every 12 inches, 
and no stone put in which reached through the wall or raised ovsj- the course of 12 inches; granite, 
or gneiss of the most sound quality, was used. 

The hydraulic mortar at tunnels, deep-cuts in earth and rock, had the proportions of 1 part cement 
to 3 sand; upon foundation- walls, however. 1 part cement to 2 J sand in volume; the same proportion 
for concrete. The sand for concrete, containing coarse and fine grains, was first mixed with water, then 
there was added to it from 2 to 2 J broken stone of the size of 14 inch, or the same amount of coarse 
gravel, and worked till the mass became uniform, and the broken stone completely covered and bedde<l 
in the mortar. Immediately after this preparation the concrete was laid and settled with a stamper 
till the surface had the appearance of an even floor : the courses were laid not over 6 inches thick. 
For brick masonry the proportion of cement to sand was 1 to 2 ; the mortar for vertical joints was put 
to the brick before laid, the brick forced into its bed in such a manner, that from horizontal and vertical 
joints the mortar readily is forced out bke sausages ; the superfluous mortar was then taken off and tho 
joints smoothed immediately : only bricks of superior quality were admitted, No. 1 for the inverted 
arch and the facing, No. 2 for the roofing-arch. 

Culverts. — In order to carry off rivers, creeks, and field-waters, underneath the aqueduct, culverts 
were constructed at a suitable depth. Their fall or inclination was 1 in 20 ; and where the upper end 
happened to be below the surface of the ground, generally the case at side-hills, a well was constructed, 
Figs. 76 and 79. The culvert, Figs. 79, 80, and 81, is one of the smallest dimensions, with bottom and 
roof of stone slabs ; that of Figs. 76, 77, and 7S, is a large one, bottom and roofing are of smooth, well- 
tnought stone, the side-walls only faced with it, while the backing of this face- work is of rough masonry 



SciLg.— 1 inch = 40 feet. 


In the body of the foundation-wall of the aqueduct, an arch of dry stone without mortar was rolled ovei 
the extrados of culvert, Fig. 78 ; after this the foundation carried further up. The fall-well at the 
arched culverts is round in plan, Fig. 77. 

The Gateway. — From the effluence cf the lake, Figs. 59 and 61, a tunnel is cut through solid rock 
180 feet in length. It has no facing of masonry, and in dimensions is kept somewhat larger than the 
general aqueduct, only below the gateway, Fig. 70, it takes the dimensions as marked, Fig. 62, except 
the height, which is here greater. The ground is uncommonly favorable for the construction of the 
gateway, offering rock-foundations throughout. As shown, Fig. 71, the channel of the aqueduct is 
widened, and the water runs through an arch in the bulkhead a a, then passes the screen-frame, a set oi 
guard-gates, and a set of regulating gates. The screen, formed of oak slabs, six inches by one, allowed 
a quantity of fish to pass through the one-inch spaces into the aqueduct. In order to prevent this, a fine 
brass netting was put over the screen, through which only veiy small fish could pass ; to prevent which 
other artificial preparations will be required. Below the wall with the regulating gates, the width oi 
the water-way is reduced to the general width of the aqueduct, by an ogee curve, in order to let the water 
into the proper aqueduct without any loss of falk 

The guard-gates with their frames are of cast-iron, made as shown in Fig. 97 ; a is the frame lined with 
metaL The sill is marked here let in stone, but in the case under description it is cut something into 
the wooden floor ; 6 is the shover with the consols c c through which the wrought-iron rod dd passes — the 
latter has a screw cut at its upper end ; e e is a nut, which is let into the caps ff and screwed. By 
turning right or left with a key put on the die, the rod rises or lowers, and the gate is opened or shut. 
On account of the considerable length of the rod, the guides k k, Figs. 69 and 70, are put on ; they consist 
of cases of wrought-iron, leaded into the stone of the wall The regulating gates with their frames are 
of gun metal, in order to obtain a superior tightness. The caps//, Fig. 70, are secured upon the saddles 
y g by bolts. In turning to the left the female, whereby the shover is raised, the saddles with the caps 
press upon the base and are kept closer and closer upon their bed ; in screwing right, however, they press 
upward. To prevent their loosening and lifting, the screw-bolts m n n are put in ; they reach down through 
two courses of stone, and there they are bent ; some of them are secured to the caps of the screen-frame. 
In shutting the gates by turning to the right, the bolts n n secure the caps // to their places and prevent 
their lifting. The masonry in all parts of the gateway is of rough gneiss in hydraulic mortar, faced with 
well-hammered stone : the partitions between the gates are of cut stone. To keep the gates and utensils 
6ecure, a stone house is erected over the gateway. 

Lixe of Aqueduct. — Having left the gateway, the aqueduct makes its way upon the left bank of the 
Croton river. After a course of one mile, it crosses Lounsberry's brook, over a culvert of 6 feet in width, 
66 feet in length, the bottom of which lies 44 feet below the top of the back-filling of aqueduct. After 
crossing some little brooks with small culverts, the line leaves this river, having followed it for 5 miles, 
turns to the left and crosses the valley of India creek 6 miles from the dam ; the culvert for the passage 
of this stream is 8 feet wide, 142 feet long, and its bottom is 58 feet below the top. A little distance 
further, the aqueduct fe tunnelled through two hills of solid rock. The first passage, called Benvenue farm 
tunnel, is 720 feet in length; the second, Acker's brook tunnel, is 116 feet long. Half a mile further is 
another tunnel of 276 feet in length, called Hoag's lull tunnel, cut through rock. From here to Sing-Sing, 
several small valleys and ravines of from 20 to 32 feel in depth are crossed by the aqueduct. Immediately 
after the last one, there is another tunnel worked through rock, called Sing-Sing tunneL 

Stxg-Sing Kill Bridge — was commonly called, while in construction, the passage of the aqueduct 
across the valley of the Kill river. Although the Kill is merely an unimportant brook, by frequent 
freshets it has worn out a large chasm, the depth of which from the top of the aqueduct to the rock 
bottom is 82 feet; the width measured at the top is 536 feet. Parallel to the river runs a street of the 
village of Sing-Sing, over which an aqueduct bridge of 20 feet in width was constructed ; a little further 
the fine of the aqueduct cut off the dwelling-house from the rest of the farm of Mr. Sing, where a pas- 
sage-way 7 feet wide was constructed. Across the stream an arch of S8 feet span was required. The 
abutment walls of this bridge are 20 feet tluck, on solid rock-foundation. The arch is constructed over an 
half oval, 33 feet in height, 4 feet thick at the spring-line, and 3 feet at the keystone ; the granite and 
gneiss for it was cut with much accuracy, not allowing the joints to be over three-sixteenths of an inch 
thick. The spandrils were carried up solid, sloping upward, thence with hauce walls and alternating 
openings, till 3 inches over the highest point of extrados : these openings were arched over with half a 
brick. Across those openings, the hance walls were connected together by bond stone. On the top of 
the small brick arches, a rubble masonry of 6 inches in height was laid, and the whole levelled off; on 
this the concrete course of 9 inches height to the extrados of the inverted arch of aqueduct. As far as 
the clear width of the bridge arch and its abutments extended, the construction of the aqueduct was so 
altered, that the side-walls were carried up 5 feet high instead of 4, as in ordinary aqueduct, and the 
arch was turned over a segment of 7 feet 7 inches long, 2 feet 8 J inches high. Bottom and side walls 
were provided with a lining of cast-iron in form and dimensions, worked in with the masonry ; whereby 
the aqueduct was rendered absolutely water-tight above these constructions. The same iron lining was 
applied also at the before-mentioned street bridge. Between the attic wall and the side wall of the 
aqueduct, spaces were left, covered over, above the attic wall, carried up in connection with the side 
walls of the aqueduct, and covered with a coping stone, the whole then filled over with earth. The 
spaces serve not only for protection against frost from without, but also for carrying off the water falling 
from the sky on the back-filling, down into the hollows. Upon the extrados of the bridge-arch, the 
drainage water runs over the tangental surface of the spandril-backing into the dry foundation wall. 
The surface over which the water drains is well plastered with hydraulic mortar. The exterior masonry 
of both the bridges is of well-hammered stone. Throughout the structure hydraulic mortar was used 
For the distance of aqueduct between the bridges and back of them to the side-hills, the rock bottom 
was prepared with steps, and a foundation wall of dry stone-masonry carried up The exterior faces of 
some thickness into the wall were laid in hydraulic mortar, and the joints pointed with the trowel. 



Scale.— 1 inch = 40 feet. 



'/ vff\ -4queduct 

DUCT. — Below some streets running across 
Sing-Sing, the aqueduct proceeds farther 
on for a mile, on quite favorable ground, 
and when on the land of the State prison 
farm, it enters into the great State prison 
farm tunnel, made 416 feet long, partly in 
rock, partly in earth. At some distance 
further, it is met by the small State prison 
farm tunnel, 375 feet, in earth: 9J miles 
from the dam, after having passed Hale's 
brook tunnel of 260 feet in length, the 
aqueduct crosses the valley of Hale's 
brook; its culvert is 6 feet in width, 131 
feet long, and 49 feet below the top of the 
back-filling of the aqueduct. One mde 
further, the fine crosses Rider's brook, over 
a culvert 100 feet long, 6 feet wide, and 
34 feet under the top of the aqueduct: 10 
miles from the dam, the aqueduct crosses 
over the highway leading from Sing-Sing 
to Tarrytown by a bridge of 20 feet span. 
Proceeding further on, the aqueduct en- 
counters some high land, through which a 
tunnel of 1S6 feet is driven; it is \\\ miles 
from the dam, designated Austin farm tun- 
nel From here the ground has various 
depressions of from 20 to 30 feet under 
the top of the aqueduct. 

At Mill river, 13 miles from the dam, 
the crossing-work is imposing. The de- 
pression of the valley is 87 feet below the 
top; the culvert or aqueduct bridge is 25 
feet in width and 172 feet in length. In 
the extension of the next two miles, in the 
vicinity of Tarrytown, at five valleys in 
succession, small culverts of various dimen- 
sions are constructed; then the aqueduct 
passes a tunnel of 246 feet in length, most- 
ly through rock, called White Plains tun- 
nel ; then Requa's brook is crossed, over a 
culvert of 25 feet below the top ; and after 
this the classical ground of Washington Irving's farm and Irving's run, the latter with a small culvert 

The next structure is at Jewell's brook, and its ravine, 17 J miles from the dam; the culvert is 6 feet 
wide, 14S feet long, 62 feet below the top. A farm-road which could not be removed, was made to run 
under the aqueduct at a heavy expense; its arch is 14 feet in width, 141 feet long. Across Wilsey's 
brook, IS 1 miles from the dam, the culvert is 49 feet below the top, 6 feet wide, and 137 feet long. 
Half a mile further there is a tunnel near Dobbs' Ferry, 262 feet, driven through earth, and designated 
Dobbs' Ferry Tunnel. Crossing Storms' brook, the depth of culvert is 40 feet, the clear width 6 feet, 
and the length 137. 

From here the aqueduct passes several small valleys of from 10 to 15 feet in depth. At Cook's run 
the culvert is 4 feet wide, 132 feet long, and its bottom is 42 feet below top of aqueduct. Dyckman's 
brook, 22 miles from the dam, has a culvert of 8 feet in width, 120 feet in length, and is 35 feet below 
the top of back-filling. Then the line crosses various unimportant valleys and creeks, with small 
culverts, and arrives in the vicinity of the village of Yonkers, where, on account of the greater inland 
extension of low ground, an abrupt curve to the left was required, followed at a short distance by 
another to the right. The aqueduct passes through the Sawmill river tunnel, which is 6S4 feet, driven 
partly through earth, partly through rock ; then it crosses the river itself, over which a bridge of two 
arches of 25 feet each has been erected. Fig. 73 is the cross-section of aqueduct at this point, with the 
longitudinal section of bridge ; Fig. 74 the cross-section of bridge with the longitudinal section of aque- 
duct; and the last, Fig. 75, is the horizontal projection of one of the flanks; close to it is the passage for the 
turnpike-road, 20 feet in width, arched over a semicircle. The next work is a culvert over Nodine's 
tun ; after which a hill of considerable height is encountered, behind winch the valley of Tibbit's brook 
pomes in the way. The tunnel under this hill is 810 feet long, driven tlu-ough solid rock, and called 
Tibbit's brook tunnel The culvert for the brook is 6 feet wide, 107 feet long, and its bed is 40 feet 
below the top of the aqueduct : it is 26 miles from the dam. At some distance several small brooks 
are crossed : one is O'Brien's run ; the largest is Acker's brook, which passes 37 feet below the top of the 
aqueduct. The last two miles of the hue are very nearly straight, the high land offering so favorable 
ground, that the upper filling of the aqueduct just disappears under the surface. Here the aqueduct 
arrives at the strait which separates Manhattan Island from the continent. 

Harlem River Bridge. — The valley of Harlem river slopes down from the before-mentioned high 
land, at a point which is 33 miles distant from the Croton dam, first at 20 degrees, to a piece of table- 
land 25 feet above tide-water, stretching over a distance of 300 feet, whence, by a second sloje, it 


reaches the water's edge. The tide-water has here a width of 6'20 feet. The bank of the island being 
of solid gneiss-rock, rises with a slope of 35 degrees to the height of the top of the aqueduct. The slope 
of this rock below water, as far as it could be examined, is steeper, and disappears under a deposite of 
mud mixed with sand and boulders. It is supposed this rock has connection with that of the opposite 
shore. In the basin formed by its depression below the strait is deposited a mass of white marble, Fig. 
100, upon which the gneiss and alluvium of sand, mixed with pieces of rock and boulders, are found, upon 
which mud is deposited, consisting chiefly of vegetable matter. 

At first it was intended to carry the conduit- water over the valley in a siphon, through iron pipes, — oh 
the side of the continent, following the surface of the ground to the water's edge, across the water of the 
river upon a stone embankment, from the centre of the river, ascending to that point of the island where 
the aqueduct starts again. Through the body of that part of the embankment, next the island bank 
which is sloping up, an arch of 120 feet in width, 60 feet high, was intended, through which a passage 
was to be kept open for navigation with sloops and schooners of 200 tons burden. The execution of 
this work was already contracted for, the dredging-macliine in operation, when the landholders of both 
the banks of the river started a lawsuit against the measure ; and an act from the legislature of the State 
was obtained, according to which, the aqueduct was to be earned below the bottom of the sea, or above 
its surface at such a height, that openings of 100 feet above high-water, 80 feet in width, had to be left 
in order to carry on the navigation. Notwithstanding estimates and comparisons of the two methods 
showed a surplus in cost of 200,000 dollars for the latter, its erection was preferred. 

This bridge has 15 arches, 8 of which are SO feet in width each, by 100 feet in height above flood-tide, 
placed in the water, and upon both the shores 7 arches of 50 feet span each ; the two abutments were 
founded on the gneiss rock, three upon the marble, seven on piles, the rock being without reach below 
the latter. With this arrangement, the conduit-water was carried across to the island in a siphon of 1 2 
feet depression. 

The manner intended of carrying the water below the bottom of the sea should here be mentioned. 
Following the slopes of the banks and the valley, 4 pipes of 3 feet diameter each, were to be laid 4 feet 
under the surface of the ground, below the bottom of the Strait ; 2 tunnels, parallel to each other, 1 2 feet 
wide, 8 feet high each, 1 2 inches thick at bottom arch, put upon concrete, side walls a nd centre wall 4 
feet thick each, rooting arches 1 6 inches thick ; the extrados of both these arches covered with a course 
of concrete of 2 feet thickness, and the whole structure, top and sides, covered again with a stone pave- 
ment 1 2 inches thick, set in hydraulic mortar ; the stone pavement was kept 24 feet below low -water. 
Each of the tunnels contained 2 pipes ; the tunnels were provided with entrances, in order to examine 
them. It was intended to carry out the work by means of a coffer-dam on each side. The estimated cost 
was 636738 dollars. 

In order to reach the foundation of every pier for the high bridge, a coffer-dam was put down, the 
coffer or box made for each of the piers of such a height as the depth of water at its site required, to- 
gether with the thickness of the mud-deposite, and 3 feet border above high-water. 

In order to take the water out of the aqueduct, and let it into the pipes, and after passing over the bridge 
re-discharge the same into the aqueduct, 2 gate-chambers, a and 6, Fig. 100, are placed. Fig. 113 shows the 
ground-plan, Fig. 112 the longitudinal section, and Fig. Ill the cross-section of the influence gate-chamber, 
(entrance into the siphon ;) c c is a basin, the bottom of which is level with the deepest line of the in- 
trados of the inverted arch ; d d are the gateways, e e the two pipes ; the influx of the water can be 
regulated by the two cast-iron double gates k k ; fg h is a waste- weir, whereby the waste water or the 
whole content of the aqueduct may be let off; f is the gateway, g the waste-weir well, h the sewer. 
The construction of the latter for the first 30 feet in length, is shown by Fig. 115; following the slope down- 
ward, it is funnelled into the shape and construction of Fig. 114, wlrich leads to Harlem river. Fig. Ill 
is the section of gateway for the waste-weir; Fig. 112 the elevation of front with the gates 11. All 
the gates are of shape and construction as shown at Fig. 69. The rod-caps of waste-weir are connected 
by the bolts ran, Fig. Ill, with the consols n; but the rod-caps of the gateways by the bolts mn, which 
are kept down and secured in the pier below, by the erosspiece n. Over the entire structure, a stone 
building is erected, arched with bricks, and covered with 3-inch greywacke slabs. The effluent-gate I, 
Fig. 1 1 1 , at the island extremity of the bridge, is of the same arrangement in reversed order, but without 
waste-weir ; it receives the water from the pipes of the siphon, and discharges it again into the aqueduct. 

Several times the question has been asked, why this bridge, being in a certain way considered a con- 
struction of luxury, has not been carried up to the full height, reaching the water-line of aqueduct, with 
the construction of the latter as upon the Sing-Sing Kill bridge ? The pipes could have been spared ; the 
erection of the gate-chambers rendered needless ; and what is most important, 2 feet of height had been 
saved, 117 feet head being left in the city, instead of 115. The reply may be : — a greater height of 
the structure would have required a larger and more compact model for the piers, or a more careful 
choice of material, and a more costly workmanship of the same ; also a greater height for the attic walls 
upon the bridge arches ; and in fine, the construction of the aqueduct itself with iron lining. All this, with- 
out doubt, would have accumulated the cost by 75000 dollars, a sum of some moment in the cost of the 
water-work. Considered as a monument, the bridge, as above constructed, has a sufficient height. 

The beginning of the construction of this bridge had been greatly delayed. It was desirable to use the 
aqueduct sooner than the bridge possibly could be finished. Down the descent of the valley, then upon 
the embankments enclosing the coffer-dams — which by degrees had formed an unbroken embankment 
across the salt-water strait — then up the island-shore to the aqueduct, a 36-inch pipe was put down, 
through which the conduit-water provisionally was led across the valley, and the aqueduct opened on 
the 4th of July, 1842. The construction of the bridge went on but slowly. 

Continuation of the Line of Aqueduct. — A short distance from the effluence-gate the aqueduct 
passes over a ravine of 30 feet in depth, immediately after which a tunnel had to be driven 234 feet 
through solid rock. This lies about 33J miles from the dam, on the land of the deceased Monsieur 
Etienne Jumell, on that account called Jiunell tunnel. Close bv this tunnel is a ravine of 38 feet in 





■Center lined 'hnHge 1 


- ■- 




depth, and another 43 feet deep. Proceeding further 34} miles from the dam, the aqueduct enters into 
the line of 10th Avenue. Without any obstacles of consequence, it proceeds hence to the vicinity of Man- 
hattanville, and 35 miles from the dam passes through Manhattan-hill tunnel, the longest of the whole 
line — worked 1215 feet through rock. 

Manhattan Valley. — Having left the tunnel, the ground slopes down to a depth of 105 feet, and 
rises up again to grade-line ; measured here, the length amounts to 4180 feet. For conducting the water 
across this valley, first an aqueduct of arcades was proposed, with arches of brick supported by piers 
of rough stone-masonry, and the aqueduct upon these in its common shape. This method of crossing 
would have preserved 3 feet of head-pressure for the conduit-water, but at an expense of $1200000, 
while the passage in pipes cost only the fifth of that sum ; this was a matter of some moment, and it 
was concluded, therefore, to make use of 4 pipes of 36 inches each. At the end of the last-mentioned 
tunnel an influent-gate, similar to that of Fig. 112, was erected, only of a greater width of basin — 4 pipes 
beinc required ; otherwise of the same arrangement, leaving out the waste-wen. At the brow of the 
opposite height, called Asylum-hill, is the effluent-gate, of the same construction entirely with the in- 
fluent-gate ; it receives the conduit-water from the pipes, and lets it into the aqueduct again. Between 



those two gates the siphon is placed, the pipes of which are partly laid in the ground ; and where de 
pressions of the ground occur, upon an embankment of earth, throughout covered with earth 4 feet high 
In order to empty the pipes of the siphon when required, in cases of repair or removing deposites of san . 
at the deepest depression of the valley, here, just in Manhattan-street, provisions were made for a waste 
weir for that purpose at each pipe ; waste-pipes were put in ; those pipes pass through the stop-cock vault 
and discharge into the waste-weir well. "\Vhen one of the pipes is to be emptied, both of its upper ends 
are closed first by the respective gates in the gate-houses, then the stop-cock in the stop-cock vault 
drawn open ; the content of the pipe makes now its way through a pipe into a sewer, which about 2000 
feet from here discharges into the Hudson river. 

Continuation of the Aqueduct-line. — The declivity of the aqueduct being from here only 9 inches 
per mile, the water rises back as far as this from the receiving reservoir, which is merely 2.1727 
miles off. To the thickness of the side walls of the aqueduct, by degrees, 4 inches have been added, 
making in all, 3 feet below, and 2 feet 4 inches at the spring-line ; in the same way the walls were car 
ried higher up to I 1 feet above the spring-line of the roofing-arch. A short distance from the effluent- 
gate the line goes through its last tunnel, called Asylum-hill tunnel ; this has a length of 640 feet, 
mostly broken through rock. Further on, for the greatest part of a mile, it was necessary to construct 



the aqueduct thus, that its sides and back-filling reached the height of 30 feet ; at the end of this, for a 
little distance, the ground rises again to such a height that the upper-filling of the aqueduct just disap- 
pears below it, then another valley comes in the way. 

Clexdenxixg Valley is the name given to the depression of ground which stretches across the high- 
lands of the island. The most favorable passage for the aqueduct is offered by a _ne drawn 150 fee* 
west from the axis of 9th Avenue, to which the aqueduct-line, coming from the 10th Avenue, is con- 
nected by an ogee-curve. The valley here has a length, or rather width, of 2000 feet, measured from 
the commencement of the upper-filling of the aqueduct, at the brow of the hill, to its disappearance on 
tiie opposite side ; its greatest depth is 50 feet below the upper-filling. Looking on the map, it shows 
that this part of the island is laid out in streets and blocks. At this place it was designed that the 
streets, after being cut through and opened, should cross over the aqueduct ; but, under such a con- 
siderable depression of ground as this, it was not practicable ; and it was concluded to pass 6 : i 

these streets, viz., the 101st, 100th, 99th, 9Sth, 97th, and 96th, underneath. The first 5 of these streeta- 
are 60 feet wide; but 96th, being a principal street, is 100. For their passage aqueduct-bridges were 
applied, of 3 arches each for the first 5 ; a main arch 30 feet in width in the centre for the road-way ; 
and two side arches, for the sidewalks, of 9 feet span each, over 101st and 97th streets ; but of 10J at 
the bridges over 100th, 99th, and 9Sth streets. During the construction of those bridges it was thought,, 
by the new "Water Commissioners, only some of those bridges might be required for passage for the' 
space of 50 or even 100 years, in consequence of which the passages for 101st, 97th, and 96th streets 
were beforehand left out; the bridges for 100th, 99th, and 9Sth streets will then be spoken of here. 

The dimensions of the different parts of these bridges are the same among all, with exception of the 
height of tiie pier-shafts only, which is determined by the various levels of pavement in the streets, but 
making only a difference of some inches. The foundation of all the piers is placed partly on rock, 
and partly on alluvial ground ; the piers themselves, as well as the arches, being constructed of gneiss 
rock ; the former of well -hammered stone, the latter of cut-stone. The spandrels of the arches are car- 


ried up solid to the line tangental to the extrados. From here hance-walls are carried up alternating 
with openings, the latter being covered over with stone slabs, at a height of 3 inches over the extrados : 
here the whole is levelled off by a rubble-masonry of stone 6 inches thick. Upon this level a course of 
concrete 9 inches thick is bedded, on which the aqueduct with its iron lining is erected ; on the outsides 
of the side-walls of aqueduct, spaces of 6 inches in width are left, in order to separate the masonry 
of the aqueduct from the attic-walls, and to carry the water, draining through the earth-filling, over 
the extrados and the spandrel-backing. The spaces of aqueduct between the various streets, and he- 
vond them to the extremities of the valley, are supported by a dry stone-wall ; stone of large size, t« 
the thickness of 2 feet, were laid upon their broadest beds over the whole course, the interstices filled 
in with smaller ones, and all levelled off with smaller and smaller broken stone to the height of 2 feet, 
on which the following course was laid in the same manner ; on a width of one foot back from the out- 
side, this masonry was laid in hydraulic-mortar, and the joints pointed. This part of the aqueduct has 
a very substantial appearance. 

The Aqueduct line continued. — Over a distance of seven-eighths of a mile, upon which a curve of 90 
degrees is turned to the left, in three various radii, the aqueduct of masonry discharges into the receiving 
reservoir ; upon that curve the ground has a depression of about 40 feet, and the over-rilling of the 
aqueduct is supported by protection-walls. Here then is the termination of the aqueduct as far as it is 
constructed of masonry ; and only some appurtenances still remain to be mentioned. 

In order to keep the air which is confined in the closed aqueduct, in communication with the atmos- 
phere, ventilators, Fig. 90, are erected at distances of every mile; buttresses a a, Fig. 91, are carried 
up on each side of the aqueduct, between which the roofing-arch is carried round 12 inches thick instead 
of 8 inches. In the centre of the arch thus fortified, a circular opening is left bordered with bricks or 
stone ; upon this border the chimney-like ventilator, Fig. 90, is erected, secured at the top by a lattice. 
The third of those ventilators is always of larger dimensions and provided with a door to pass into the 
interior, Figs. 89 and 88, in order to facilitate examination and repair of the inner parts of the aque- 
duct in cases required. The one shown by Fig. 90 is put up before crossing Olendenning valley. The 
greater number of them are made of white marble, the rest of gneiss. There are of the latter kind 1 1 
in all, and 22 of the former. 

At suitable points of the aqueduct line wasto-weirs are put in to draw out the water when required. 
There are six on the whole fine, with exception of that hi the gate-house before Harlem river bridge. 
A gateway, Figs. 82, S3, 84, and 85, is formed according to the marked dimensions ; the waste-water 
passes through a pah- of gates, 6 6, falls into the well c c, and discharges over d into the sewer e e. The 
S'ates with the gateway are constructed entirely as shown hi Fig. 97, and already described. When the 
water rises higher than 5 feet 9 inches, measured from the deepest point of the intrados of the inverted 
arch, it runs over the lip of the breast- wall//, and falls likewise into the well c. By means of timber 
or planks i i, put against the post h, and slipping in the rabbits r/ g, provision is made to keep the water 
in the aqueduct higher at pleasure, consequently over the mentioned 5 feet 9 inches. In the platform 
at k, an opening, provided with a trap-door, is left, through which the planks i i can be put in and 
taken out. Above all, a stone house has been erected. From without, the platform can be reached 
by the door and over a small stair. At m, Figs. 84 and 85, a rabbit is cut in the side-walls of the 
aqueduct, into which timber may be slid in order to shut off the same. Those waste-weirs at their 
places serve likewise for ventilators ; the one just described is put at 142d street: those on the continent 
are of the same description, with unimportant differences adapted to locality. 

Tue RECEiviNG-RESERvom, is built between 7th and 6th avenues, and S6th and 79th streets ; its 
area is 37.05 acres, including the top of the embankment, or 31 acres of surface of water. By means 
of an embankment it is divided into two divisions ; the north one has a depth of 24 feet, measured 
down from the top of the embankment, and is filled with 20 feet of water; the southern division is 29 feet 
deep below the top of the embankment, 25 feet of which is water. Those depths, however, are not 
throughout the same ; the rock-bottom near the southern embankment lies lower than this — near the 
northern embankment, higher. The contents of water amount to 150000000 gallons. Each division can 
be used as a single reservoir for itself, while the other may be emptied for inspection and repair. 

At the influx of the aqueduct at S5th street, west side of the reservoir, the street-level is equal with 
the top of the embankment. All the other parts of embankment had to be carried up more or less in 
order to reach the top, the ground being lower ; and at efflux of the reservoir in 80th street, east side of 
the reservoir, it is 38 feet below the top. 

All the embankments are of earth, the interior puddled with clayish earth or loam. The sides on the 
streets and avenues are protected by dry walls of stone, their outside being laid in lime-mortar and the 
joints pointed, Figs. 127 and 12S. The inside slopes of the embankments washed by water, are protected 
by a dry stone pavement of 15 inches thick. At the bottom of the reservoir the bare rock or earth is 
left without any artificial contrivance. 

In order to keep the surface of both the divisions at a level, a connecting or communicating-pipe, Fig. 
125, has been placed, of which Fig. 123 is the section; the pipe is bedded upon rock, surrounded and 
supported by concrete : halfway a stop-cock is put for shutting and opening the pipe ; over this cock a 
circular well is erected, and carried up to the top of ;he embankment. Upon the top of the well 
two caps are placed, on which a nut is screwed, like that at Fig. 94, i ; by means of which, in con- 
nection with the screw-bar, the stop-cock can be drawn and shut. 

When the water has reached its height in the reservoir — viz. 4 feet below the top of embankment — 
and the rising still continues, the surplus water falls by itself into the waste-weir well Through the 
same way 3 feet more water can be drawn off from the surface when required, by taking out the tim- 
bers. Over the top of this waste-weir well, a bridge with a brick arch is erected, for the passage on 
the top of the division-embankment. 

The influent-gate, Figs. 120 and 121, receives the water from the aqueduct a, by the gate-chamber A, 
%nd lets it either directly by the gateways eee over the sluice-channel c c into the northern division, or by 



the gateways fff through that part d d of the aqueduct 'which is built in the body of the western embank- 
ment leading into the southern division. The various apertures of the gateways of the two entrances are 
separated from each other by means of jambs of cut-stone 9 inches thick, covered over at the front, 
in the gate-chamber, with stone lintels, Figs. 116 and 119,at^(/; in the rear at h h, however, the passages 
are arched over with half a brick, Fig. 119. The gates, with their frames, are made as shown at Fig. 97 ; 
the gate-caps rest partly in the walls and partly upon the posts 1 1. In order to prevent their rising, in 
screwing the gates, consols n n are projected, to wlrich the gate-caps are secured by the bolts n in. By 
those two sets of gates, the water-influx to the divisions of the reservoir can be regulated completely. 

Over the whole a stone building arched with brick has been erected, and covered with flags of grey 


Scall:.— 1 inch = 40 feet 

The efflux from the reservoir is arranged in such a manner, that the water may be drawn either from 
the one division or from the other, or from both at once, each division having its own separate outlet. 
Three pipes, coming out of the northern division, run in the body of the eastern embankment, protected 
by a vault built in the same. At the southern extremity of the vault, upon the axis of SOth street, the 
pipes are united to 3 others, leading from the southern division, making 4 after the junction. Nos. 1, 2, 
and 3, carry the water to the distributing reservoir for the lower part of the city ; No. 4 is for the sup- 
ply of the east side of the upper town. 

The arrangement of efflux is thus . a a a, Figs. 123, 124, 126, 127, and 181, is a tower, erected with sub- 
stantial stone walls ; in the open side, fronting the reservoir, is put the gate-framing with the screen b b. 



Scale.— 1 inch = 40 fuel. 



the same consists of two frames, of 1. 2-inch white pine timber; the outer is filled with 1-inch oak slats 
6 inches wide, put 1 inch apart, Fig. 131 ; the upper part is covered with plank; the inner, or 2d frame, is 
left open as far as the just-mentioned planking reaches. Below this the gate-apertures are left — 4 of such 
are in the tower, Figs. 123 and 127 ; at the tower, Fig. 124, they are of 2-inch pine plank, connected by 
pieces of plank nailed across and slid in wooden grooves ; some of them are opened by sliding down, 
some by sliding up. Opening and shutting is effected by iron rods reaching up to the gate-caps ccc, Figs. 
126, 127, and 131. On the top of each rod a screw is cut, which goes into the nut put upon the gate- 
caps ; the nut and screw are shown by Fig. 93, at d c and i. Above this gate and screen-frame the tower 
is carried higher up and roofed over. Fig. 131 is the elevation of the tower-pavilion; Fig. 127, its section, 
and longitudinal section of bridge connecting the tower with the embankment. In the interior of the 
tower, Fig. 127, some timbers are put for support of the gate and screen-framing when the gates are 

Hmsf.-r. ff,7ff 


42?- Sired. 
Scale. — 1 inch =40 feet. 

eiosed. At the figure named, / shows the wing- walls of the tower, and g a breast- wall, being carried 
Hp against the bottom of the reservoir. Although Fig. 127 here is the section of Fig. 124, just as Fig. 
131 is the elevation of Fig. 123, yet the arrangement and construction of the two are alike, except in 
some dimensions, winch at Figs. 123 and 131 are smaller. 

In the rear- wall of the tower are the mouths of the pipes ; the latter for some distance are bedded In 
and covered over with concrete, Figs. 123, 124, and 130. When the pipes Nos. 2, 3, and 4, coming from 
the northern division, have passed the line of the waste-weir sewer, D E, Fig. 123, they enter into the 
pipe-vault, Fig. 129 and Fig. 12S ; here they join with the pipes Nos. 1, 2, and 4, and so pass on. The 
letters h h show the stop-cocks ; at i is a passage with stairs starting down from the avenue. In order 
to prevent all sudden opening and shutting of the stop-cocks or sUdrng-valves, consequently the pushing 



of the -water, and to obtain a water-tight sit, a set of conical -wheels and the crank, Fig. 98, -were put in 
connection -with the stop-cock. 

There are for the supply of the upper town, at the west side of the reservoir, two other effluent-gates, 
of similar description and equal heights with the corresponding ones iu the same reservoir-division ; yet 
they have their outlet through one pipe only. They are, together with the towers, of smaller d im ensions 
in length and width. 

The Aqueduct-Line continued. — From the mouth of the pipes at the 6th Avenue, the aqueduct, consist- 
ing here cf three pipes, 36 inches each, 4 feet under ground, runs along 80th street, bends round the corner 
into 6th Avenue, proceeds here a distance of 2.176 miles across three depressions of ground and two 

Scalb.— 1 inch — 40 feet. 

Mights. On the summit ot the latter air-cocks are put, to allow the air to escape. At the lowest points 
of the depressions there are outlets, in order to get rid of the sand which might collect here. 

The Distributing Reservoir is also divided into two divisions, an eastern and a western, by means 
of a division-wall. Each has a separate inlet and outlet, and may be used as a reservoir for itself, while 
the other division is emptied. It is erected on the top of Murray hill, the greatest part being above 
ground; as for instance — the comer marked by x, is 49 feet above the street; y, however, only 39 feet. 

The outer walls a a of the reservoir, of 4 feet thickness, the inner of 6, connected together with the 
cross- walls c c, 4 feet tluck, form the chief mass of the enclosure of the basin. The cellules d d, between 
the cross-walls, are arched over 12 inches thick with bricks; their spandrels, of some feet in height 



backed with stone masonry ; then filled over and levelled off with concrete to a height of 6 inches above 
the highest point of the extrados of those brick arches. The division-wall is of concrete, faced with 
rough stone-masonry, Fig. 146. The bottom of the basin is puddled with earth, over which a course o,' 
concrete, 1 2 inches thick, is laid ; the sides are puddled, and slope up 1 foot in 4, horizontally, for 1 6 
feet in width ; then 1 to 1 to the coping of the tuclosure. The lower part of this slope is covered with a 
course of concrete, 12 inches thick; the steeper upper part is protected by a pavement 15 inches thick, 
laid in hydraulic mortar. The slopes of the division-wall have the same protection. The upper-filling 
of the cellule-arches is likewise of puddle, except 2 feet next the slope-pavement, and 2 feet below the 
flagging of the platform, Figs. 134, 137, 138, 144, 150, and 151, which will prevent the frost from 
penetrating into the puddle in parts not covered with water. 


VraanLon <i*&g,, #gy -«r. < c Q,2j$&'+<™>9 W 

Drain. O Jhfbientja/ier fff^i Influtntpijws £3 Drain 


LC71 i>/ Dn-ifi'su ?v<2,Y 

140. 139. 


Cer*7i£ct1n>j-7tip.e Sltastt v 

Scale. — 1 inch = 40 feet. 

The total length of the entire structure, measured at the top of the cornice, (not in its projection,) u 
120 feet; so the width. The basin is S86 feet square, 42 feet deep, and when filled with water 38 feet, 
contains 21000000 gallons. In order to collect and drain off any water which might filter down 
through the embankment i, and through the walls 6 b, there are left in the cross- walls cc, small open- 
ings nn, Figs. 134, 135, 143, 141, 150, 151, by which the water may drain from cellule to cellule with- 
out the structure. Out of the northern side, the drain-water runs through the two sewers//, Figs. 134, 
135, 136, 141, 142, through the receiving-sewer <jr/, to the street-sewer hh. The southern Dart of the 
structure makes its drainage in an opposite direction— viz. through the drain-sewer i to the well k, 
Figs. 134, 135, from which it is carried off by the street-sewer of 40th street. Fig. 140 shows the 1cm 


gitudinal section of the sewer q, the cross-section of the well k, with the mouth of the streot-sewer ', 
the construction of wliich is given by Fig. 139 ; the sewer ii has a like construction as Fig. 142. 

In order to draw off entirely the water from the bottom of each division, when required for cleansing 
or repairing them, 2 little wells are put in, m ?n, Figs. 133, 137, and a slight descent of the bottom towards 
them, from off all sides, arranged. In those wells the last of the contents collect, and is drawn away by 
pipes marked o o in the above-mentioned figures. The pipes discharge the water into the receiving- 
sewer g g ; by the stop-cocks p p, those pipes can be opened and closed. 

In order to keep the water of both divisions on a level, a 36-inch connecting-pipe is put through the 
division-wall. Fig. 185 shows the ground-plan of the well in dotted lines. Fig. 133 is the top of the 
well, with a square opening formed by jutting over the coping-stone. Fig. 139 is the longitudinal section 
of pipe, stop-cock, and well 

For letting out from the reservoirs the superfluous water, a waste-weir well, in 2 descents, or for 2 
cascades, has been constructed in the body of the division-wall. That water which fells from the open- 
ing of the bridge s s, Figs. 132, 137, 13S, 140, covering the first well, filLs the water-bag below, wliich is 8 
feet deep ; it passes through the opening s, makes then the second fall down the well s, fills its water- 
bag, and is carried off through the sewer s h into the street-sewer of 42d street. The construction of the 
sewer h is shown by Fig. 141 ; it has here, as well as in g, a bottom and arch of stone. 

The pipes 1, 2, and 2, 3, having made their curves running parallel with each other, they end in the 
pipe-areas 1 1, and the aqueduct itself terminates herewith. The just-mentioned figures show the course 
of the pipes: Figs. 136 and 140 the cross-section of the course at the entrance into the structure of the 
reservoir; and Fig. 134 the parts near the stop-cocks. Fig. 137 is their longitudinal sectioa and sec- 
tion of the pipe-area: the same figure shows also the bedding and wrapping of concrete round the 
pipes in the embankment ; it exhibits also the cut-off wall u. 

For the effluence of the water into the distributing-pipes, an effluent-tower i>, with gate-Srame «,, is 
erected for each division. Figs. 143, 145, show the ground-plan ; Fig. 146, the elevation; Fig. 150, the 
side-view; and Fig. 151, the section. The gate-frame has a screen at the outside, in the rear of which is 
the gate-frame itself ; both are supported by a breast-wall, over wliich the water falls upon the interior 
bottom of the tower, wliich is S feet below the top of that wall. In the rear wall of the tower is put 
the entrance into the city-main. Each of the towers has a pipe x and z, wliich are connected hi the 
pipe-vault by the cross-pipe y ; x runs to the eastern part of the town, z to the central part, and tz to 
the west part, for distribution. The ground-plan shows the way in wliich all 3 pipes can be supplied 
by the one set of gates, or the other, or by both together. The arrangement for the outflow of water 
answers, therefore, completely, the purpose — to empty the one division, entirely, while the other re- 
mains filled 

At the lowest points of the pipes x, y, and z, draining-pipes with stop-cocks are put in, to let out into 
the sewer-pit k k any sand that may collect here. The way to work the gates from the caps, as well as 
the upper structure of both the towers, is shown by Figs. 145, 146, 150, and 151. 

The platform of the reservoir is guarded by an iron railing. At the elevation of 119 feet above the 
leTel of the sea, it commands a complete view of the west and east of Manhattan Island, as well as oi 
tl_3 south part of the city, with New York bay, and at a greater distance hi that direction, the Atlantic 
ocean. This view is exceedingly beautiful, and is one of the finest in the world. 

Distribution of the Watek. — From tliis reservoir, the distribution of the water is made. The above- 
mentioned three 36-inch pipes convey it to the lower town, which is built closer and closer the fur- 
ther down one goes ; 134 miles of pipes of all sizes, between 36 and 4 inches, conduct it through the 
streets, and feed several public and private fountains ; these pipes are laid down in the centre of the 
streets, or as near so as possible. The branchings and crossings are made by means of single or double 
sleeves cast together with a main-piece. The pipes are put together with faucet and spigot, 6 inches 
deep ; at the smaller pipes, 4 inches. The pieces have a length of 9 feet, eacli piece making thus 9 feet run 
of water-conduit when put together. Before laving down, they were proved with the hydraulic press, 
with the pressure of 200 to 250 pounds to the square inch. 

At the corners of streets where crossings and branchings occur, stop-cocks are put in, in order to cut 
off districts of pipes, when this is required for alteration or repair. Those pipes that rail off from the 
street pipes, leading into the houses, are J to 1 inch wide, made of lead, connected to the main-pipes by 
boring. Such a house- pipe has either a mouth-cock under the outdoor steps, or leads to the kitcheu 
which in this country is in the basement. To feed bathing-tubs or bathing apparatus, a pipe some- 
times rises to the upper-story bedrooms. 

Pipes branching off for the hydrants, placed at convenient distances, are for the most part of cast-iron, 
oranching off from the mains by sleeves ; at the larger-sized pipes, by means of boring. The hydrants, as 
far as they are above ground, are protected by a cast-iron case to keep off frost, heat, and damage. For 
the extinguishing of fires, the engine-hose is screwed to the muzzle of the hydrants. At the harbor, 
pipes are branched out, terminating at the bulwarks, in order to supply the ships, and fill the water- 
casks on board by a hose. 

The cost of this aqueduct amounts to 8575000 dollars, including purchase of land required, extinguish- 
ing of water-rights, and some unfinished works. This amount is within 5 per cent of that estimated by 
the chief engineer, Mr. John B. Jervis, and the percentage occurs chiefly below the estimate. To tliis 
is added 1800000 dollars, the cost for the distributing-pipes. 

The first two millions had to be raised at an interest of 7 per cent, and are payable from 1S47 to 1857. 
For the rest, 5 per cent is paid, and to be redeemed from 1858 to 1880. 647 157 dollars was the discount 
for issuing the loan, which, together with the interest paid already during the construction of the work, 
wings the total expense to 12500000 dollars. 

The annual interest fur this capital amounts to 665000 dollars, wliich is collected by a direct water- 
tax, and some indirect taxes ; by meaus of an existing sinking fund, the capital will be redeemed by 
degrees. The water-tax amounts to 10 dollars for a house of middle size ; manufacturers, hotels, bathing 





establishments, distilleries, livery-stables, bakeries, sugar-refineries, breweries, slaughter-houses, ete., and 
fillips, pay according to extension and size. 

ARCHES. Arches are of various shapes, as Pointed, Elliptical Segmental, and Circular. The outer 
surface of the arch is called the cstrados or back of the arch, the inner or concave surface, the intrachs, 
or the soffit; the joints of all arches should be perdendicular to the surface of the soffits. The stones 
are called arch stones or voussoirs. The first course on each side are termed springers, which rest on the 
imposts or abutments. In case of a segmental arch, the course beneath the springers are called skew- 
backs. The extreme width between springers is called the span of the arch, and the versed sine of the 
curve of the soffit, the rise of the arch. The highest portion of the arch is called the croicn, and the 
centre course of voussoirs the key-course. The side portions of arches between the springing and tho 
crown, are termed haunches or flanks. All arches should be well sustained by backing on the haunches 
called spandrel-backing. The line of intersection of arches cutting across each other transversely is 
called a groin and the arches themselves groined arches. See Bridge. 


ARCHITRAVE. The lower of the three principal members of the entablature of an order, being 
the chief beam resting immediately on the column. 

ARCHIYOLT. A collection of members in the face of an arch, concentric with the intrados, and 
supported by imposts. Archicolt of the arch of a bridge — the curve line formed by the upper sides of 
the arch-stones in the face of the work ; it is sometimes understood to be the whole set of arch-stones 
which appear in the face of the work. 

AREOMETER. An instrument for measuring the density or specific gravity of fluids. 


ARRIS, the intersection or line, on which two surfaces of a body forming an exterior angle meet 
-ach other. Although the edge of a body may in general mean the same thing as its arris, yet, in 
building, the term arris is restricted to those two surfaces of a rectangular solid, on which the length 
and thickness may be measured, as in boards, planks, doors, shutters, and other framed joinery. 

ARTESL\N WELLS, so called from a mode practised in Artois in boring for water. 

ARTESIAN WELL OF GRENELLE, Boring Apparatus of. About the year 1824, M. Peligot, 
one of the superintendents of the hospitals at Paris, suggested the idea of sinking a well upon the Arte- 
sian principle, and ■workmen were sent from Artois for the purpose ; whilst this was being effected, M. 
Mulot, a smith, became interested in the operation, and turned his attention to the subject; he was 
consequently employed by the Marchioness de Groslier to sink one at Epinay ; success attended his 
tflbrts, and he was nominated to attempt one at Grenelle. The primitive soils, according to M. Arago, 
are but rarely stratified, or are found in regular beds. The fissures in granitic rocks, the crevices sepa- 
rating the contiguous masses, have but little width or depth, and do not frequently communicate with 
pach other ; m such soils the waters of filtration have but limited outlets, each film or tlnead termina- 
ting its course alone, without receiving any increase from others in their descent. The springs being 
numerous in the neighborhood, it was not thought probable that any vast quantity of water could be 
obtained, as the whole of the rain penetrating the earth was supposed to pass off through various open- 
ings hi the sides of the hills. 

The secondary soils, which are composed of a variety of rocks, in general take the form of immense 
reservoirs or basins, the centre being considerably depressed, or the extreme boundaries of it greatly 
elevated Within this basin, hills, and often mountains, arise, apparently destroying its original charac- 
ter. The stratification of the secondary formation is in regular beds, some of which are of enormous 
thickness, composed of sand or grit, and very permeable ; these permeable beds, as they rise towards 
the extremities of the basin, become bare on the sides of the mountains and hills. The rain-watei 
which falls on the earth, after penetrating it, forms one continued sheet, which pursues its course with 
great rapidity when the beds have a great declivity, and, reaching the lowest point, is accumulated in 
vast quantities. One chalky or calcareous stratum, which is furrowed out in all directions, and par- 
ticularly in the upper portion, allows the pluvial water to pass with great facility, and also to circulate 
through the mass to a great depth : and hi this peculiar stratum the wells both of Grenelle and Rouen 
have been bored. 

The tertiary soils are stratified, and composed of many beds placed over each other, and separated 
by clean and well-defined joints, like the secondary, on which they rest ; these basins are of less extent, 
and derive their form from the rectifying of the beds, the elements of which they are constituted being 
the same as those found on the neighboring bills. The several beds are arranged in a regular manner, 
and their separation is formed by a layer of sand, through wliich the water freely percolates ; in these 
several sandy fissures it acquires force as it descends, and at great depths, its pressure being augmented, 
the flow is rendered constant. 

These soils are undoubtedly the best for sinking Artesian wells, because they have at their base 
courses of sand lying on impermeable clays, and are less subject to dislocation or rupture than rocks 01 
the oldc- formation. Such strata are easily examined, and are usually found rising from the centre ot 
the basin, and following an inverse direction to that of the inclination of the water, which, like a sub- 
terranean river, pursues a downward course till it meets with an outlet. They frequently become bro- 
ken, when the water they contain weeps into small rivulets and is carried away on the surface. 

Where the well has been bored at Grenelle, the upper stratum or tertiary deposite is 41 metres in 
thickness; the next is composed of chalk mixed with flint, 99 metres; then a gray chalk, without any 
silex, 25 metres ; to this succeeded a gray chalk, in which were iron pyrites, 341 metres ; then a wealden 
c l a y. g ra y sand, and a sandy clay, in which were found ammonites and other fossils ; the whole depth 
bored through being 548 metres, or about 1198 feet. 

Before giving the description of the apparatus used in boring this well, we will give a short sketch 
of the difficulties encountered and overcome by M. Mulot, to whom the direction of this great work had 
been intrusted. 





M. Mulot commenced boring in 1833 ; he easily pierced the tertiary sands, winch arc at Gienelle 13C 
feet thick, but shortly after having reached the chalk, at the depth of 377 feet, the sides gave way and 
rilled the bored space, which was cleared again, after fifty-seven days' labor ; this happened in June, 
1S34. In May, 1837, the borer had reached 1246 feet, when the valved-spoon, together with a rod 262 
feet long, fell to the bottom of the hole and were shattered to fragments ; the weight of the mass was 
100 cwt. Many contrivances were proposed — some even put in execution — but in vain, till M. Mulot 
had the idea of wearing the ends of the fragments, and thus extracted them, fifteen months after the 

In April, 1S40, the instruments were wearing out rapidly, while they were making little headway 
through the hard chalk, when, being raised to a considerable height, the boring-screw fell, and was 
buried in the compact rock to the depth of 75 feet. It became necessary to bore all round it in order 
to free it, and after many months of labor this new obstacle was surmounted. 

In December, 1840, the spoon detached itself from the rod, causing a little delay in the operations of 
SI. Slulot, who bored a hole in the sides of the well and pushed the separated instrument into it. This 
was the last impediment to overcome, and the 26th of February, 1841, the rod suddenly sunk several 
feet; immediately a column of warm water 1797 feet high, equal to the pressure of 53 atmospheres, 
rose from the bosom of the earth, and poured upon its surface S00.000 gallons of water, having a tem- 
perature of 79 Falirenheit. 

But, besides boring, it was necessary to give support to the sides of the well, which would fall hi, 
unless composed of material more consistent than earth. A tube of a certain calibre is first introduced, 
then another smaller one slipped within the first, and so on ; but should the boring be deeper than ex- 
pected, it would become necessary to withdraw these tubes in order to replace them by larger ones, 
because the last must be of sufficient calibre to allow the rod to work. At Grenelle it was necessary 
to chaw off five series of tubes, and to bore larger holes to introduce tubes of a greater diameter. 

The following is a table of the strata bored through. 

Nature of the Strata. 

Foundation of a basin 

Alluvial soil, composed of rolled flints and gravel 


Plastic clay, lignites, iron pyrites, and sand, penetrated by sul 
phuret of iron 

Marl and calcareous sand, containing nodules of compact lime- 

Chalk and silex in lumps 

Hard gray chalk with silex 

Gray chalk, very hard, alternating with more soft chalk 

Green chalk 

Blue chalk with clay 

Black and blue clay, with strata of green sand, containing iron py- 
rites and fossils 

Argillaceous sand 

Green sand 







on the surface 




Description. — The apparatus consists of a crane with four beams A, iron-bound. At the summit 
there are four pulleys of cast-iron B, on these the chains C pass ; these cltains also go through two 
otiia.' moveable pulleys D D'. The chains C, attached by one end to the guide-strap of the pulleys 
D D', are hooked by the other extremity on the conical drum E E', around which they are wound hi 
opposite directions. By these pulleys the iron bars F, 26.24 feet long, to which are attached the bur- 
rowing instruments, are lowered and raised. 

To raise the rods, eight horses are harnessed at G, Figs. 158 and 159, which being set in motion, one ot 
the chains passing through the pulley H coils round E, while the other chain is unrolled. The pulley D, w 
which the rod F is suspended by means of a hook, is raised, and brings up all the boring apparatus. 
When tins pulley has reached the top of the crane the second pulley D' is made fast ; then the bar just 
raised is taken off by men standing on a ; the hook is fixed to the next bar, and the horses are driven in 
She opposite direction. While the pulleys are exchanged, the top bar is seized by the crank J, 
placed at the orifice of the well to prevent it from falling. The cranks J are formed of two strong iron 
plates, between which are set two eccentric chaps J' J 2 , which allow the rods to ascend, but prevent 
their falling back. 

Oue man is necessary to lower the rod, which is accomplished by pulling or loosening the break, 
Figs. 15S and 159, at pleasure. This double break consists of two large hoops K K', surrounding the 
(hum L, wluch is covered with a thick sheet of iron ; one of the extremities of the hoops is fastened to 
(he horizontal beam M, while the other is kept in place by a square placed out of the works, and opened 
or closed by a lever. 

The next thing to be considered is how the rod is turned. It is adapted to the wheel N, 
which is made to communicate with the wheel, Fig. 163. The toothed-wheel N, is for this purpose 
changed from the position it occupied, Fig. 158, to that represented Fig. 162, corresponding to the 
axis of the well ■ a square hole is made in the centre to receive a square bar of iron .2624 of a foot 




square and 1 3 feet long, which is adapted by one extremity to the boring-rod, and by the other is sus- 
pended to the hook of the pulley D. When the wheel N is fixed to the rod it is adapted to its inter- 
mediate toothed-wheel P, fixed to a wooden frame close by the crane. The wheel P is put in connec- 
tion with the great wheel Q, placed over the wheel R, to which two, and sometimes tlnee horses are 
harnessed. The burrowing-rod is suspended by chains run into a ring g, Fig. 159, and coils round the 
drum S, Figs. 15S and 163', situated on the other side. The wheel T serves to raise or lower the 

When the wheel R is put in motion, the rod.receives the movement of rotation imparted to N by tha 
toothed-wheel P. The men at T allow the rod to descend slowly. The pulley D' would be in the way 
during the operation, it is therefore fixed by a pin to the links of the chain. 

Explanations of the Figures. — Fig. 158. — A vertical and longitudinal section of the apparatus in a 
plane passing through the axis of the well, and of the wheel used to lower and raise the borer. 

Fig. 159. — A horizontal section of the wheel G, made above the breaks; the two conical drums, 
•wound winch the chains are wound, being omitted. 

Fig. 160. — A horizontal projection of the drum L, and of the breaks. 

Fig. 161. — A front view of the two frames XJ U', placed in the horizontal beam, near the wheel G. 
Within these frames two smaller frames are made to slide ; they have wooden rollers, u and u', and are 
intended to support and guide the chains C, to the drums E E'. These chains, when slack, rest on 
the rollers v v'. The frames XJ and IT' have their superior part in contact with the beams V and V, 
which are fastened by one extremity to the crane, and by the other to the strong bearer, X. The pillow 
of the axis of the wheel G, rests also on this bearer. 

A flooring, Z, connects the wheel to the crane, and places within the reach of the workmen the parts 
just described. 

Fig. 162. — Vertical and transverse section of the apparatus, whose plane is perpendicular to that of 
the section, Fig. 158. 

Fig. 163'. — A view of the drum used for supporting and lowering slowly the borer as it sinks. 

Fig. 104.— Plan of the wheel R, Fig. 162. 

Fig. 165. — A profile view of the frame and wheel N. 

Fig. 166. — A plan of this frame, which slides in grooves made in the beams 0, Figs. 15S and 162, 
on small friction-rollers. The small flooring n, gives passage towards the centre of the wheel 2s T , in 
order to adapt the rod in it. 

Fig. 167. — Front view of the wooden support to the toothed-wheel P, Fig. 162. 

Fig. 168. — A horizontal section of this support, and plan of the wheel. 

Figs. 169 and 170. — A front and profile view of one of the moveable pulleys, D D', with its guide- 
ttrap, giving attachment to the hook d, to which is suspended the borer by a ring. 

Figs. 171 and 172. — An external view of the crank J, with a section following the line 1 — 2. 

While the boring goes on, this is set over the orifice of the hole ; to this end, two semicircular pieces 
j' are attached to the plates J, and rest on the ground. The rods pass between J and the nippers 
J 1 , J 2 . As long as the rods are raised the nippers yield; but as soon as they remain motionless, either 
to change the rods or for any other motive, the arcs through their eccentricity press against the bars 
and prevent their descent. To secure them further, their other sides are held by the force-screws p. 

Fig. 173. — A fragment of galvanized iron tube, 0.016 of a foot thick, used as a conductor to the water 

Figs. 174 and 175. — Pincers used for the extraction of fragments of wood or other matters. 

Fig. 176. — Section of the foregoing, following the line 3 — 4. 

Figs. 177 and 178. — Pincers for withdrawing the tubes. 

Fig. 179. — A horizontal section of a branch in the direction of 5 — 6. 

Figs. ISO and 181. — Detads of an instrument called Caracol, used to withdraw fragments of the rod 
when they have penetrated into the parietes of the welL 

Fig. 1S2.— A plan of the instrument. 

Figs. 183 and 184. — Screwed rods composing the borer. The superior bar has a hook also vised to it. 

Figs. 185 and 186. — Rods united by means of pins, the heads of which are buried in the thickness of 
the bars. The end of one is fissured, in order to receive the end of another rod. 

Figs. 187 and 188. — A ring which is attached to the rods by three pins. 

Figs. 189 and 190. — A cliiseL called Trepan, used to perforate the liard rocks which it is necessary 
to break and to crush at the same time. There are three edges, a, b, c. The edge a is double, 6 and c 
are turned in opposite directions. This implement will cut the rock and crush it in whatever direction 
it is turned. 

Figs. 191 and 192. — A valved spoon, used in sands and clays almost rendered liquid by the water in 
which they are in suspension. It consists of a long cylinder in sheet-iron, open at both extremities, the 
inferior being strengthened by an iron ring with a sharp edge. A little above this ring there is a disk, 
at the centre of which a round hole has been perforated. This opening is perfectly closed by an iron 
ball. When the spoon is lowered into the hole the sand pushes away the ball, which, however, falls 
back by its weight, closes the orifice 6, and allows the extraction of the sand. The ball is prevented 
from rising too high by the perforated disk c. 

Figs. 193 and 194. — A vertical section and external view of the borer, used to enlarge the hole. It is 
very solid, and consists of a hollow cylinder, whose inferior extremity is furnished on its circumference 
with fluted knives, of which there are several of different dimensions. 

Fig. 1 95. — A view of the underneath part of the preceding. 

Fig. 196. — Shows the mode of attachment of a knife to the ring, and also a front view of the knifa 
The knives are firmly attached to the inner ring, and are surrounded by another ring of greater diame- 
ter. The whole is traversed by a pin. 

ASH See Woods, varieties of. 




ASPEN, See "Woods, varieties of. 

ASH, See Woods, varieties of. 

ASHLAR, hewn stone used for the facings of walls. If the work he so smoothed as to take out the 
marks of the tools by which the stones were first cut, it is called plane ashlar ; if figured, tooled ashlar, 
or random tooled, or chiselled, or bousted, or pointed : if the stones project from the joints, it is said to 
be rusticated. 

ASHLERING, in carpentry, the fixing of short upright quarterings between the rafters and the floor. 

ASH-PAX. In locomotive engines, an iron box attached to the fire-box to receive the ashes from the fire. 

ASPHALTUM. Native bitumen. Its chief application is in the construction of roads and pave- 
ments, for roofing, and for protecting buildings from dampness. Its application to roads and pavements 
in this country has been unsuccessful, but it is still in use in Paris and other European cities. 

Asphaltum varies considerably in purity, according to the quantity of different earthy substances 
mingled with it. When nearly pure its color is almost black, or dark brown, and it does not soil the 
fino-ers : when rubbed it gives off a pitchy odor. In combination with other substances it forms a mas- 
tic, which is applied in a liquid state to kitchen and stable floors, pavements, &c. The principal ingredi- 
ent iu " The Calcareous Asphaltum " which is found at Seyssel near the Jura Mountains, is a dark brown 
bituminous limestone. The stone is reduced to powder and mixed with a portion of mineral tar when 
intended to be applied as a cement, as in covering roofs, lining tanks, &c. ; but when intended for floor- 
ing or pavements, sea grit is used in addition This is melted and run into moulds about 1 8 inches 
square, by 6 inches deep, or formed into blocks weighing from 112 lbs. to 130 lbs. each. In this state 
it is sold for use, and is remelted on the spot where required, in cauldrons heated on small portable fur- 
naces, with the addition of 1 lb. of mineral tar to 1 cwt. of mastic. 

The only kind of tar to be used in this mixture, is that with which the limestone is impregnated. If 
the mastic is required to he very stiff, as for paving kitchen floors, a smaller proportion of tar is to he 
used, with a larger proportion of grit. To convert fine asphalte into coarse, 30 lbs. of fine clean grit are 
to be added to 112 lbs. of mastic, with from 1 lb. to 2+ lbs of tar. 

In applying asphalte to the floors of cellars and basements to exclude dampness, an inverted brick 
arch laid in asphalte as a cement should be used. Asphalted bricks are also prepared by heating them, 
and placing them in rows upon a flat surface between gauges, allowing a layer of mastic a quarter of 
an inch thick to be laid over them : the brick are then separated with a knife before the mastic is quite 
set. The brick are also prepared by dipping the ends in boiling mastic. 

The thickness of asphaltum used for pavements varies from half an inch to an inch and a quarter, 
the former for floors and the latter for carriage-ways : half an inch or five-eighths is sufficient for roofs 
and the coverings of arches, and about a quarter of an inch is sufficient for the ground line of brick- 
work to prevent damp from rising. An asphaltum surface admits of easy repair. By placing hot mas- 
tic npon the place requiring it, the fresh material will readily adhere to the old work if free from dust 
or moisture. Asphaltum is used in oil painting; for which purpose it is first dissolved in oil of turpen- 
tine, by which it is fitted for glazing and shading. 

ASSAYING. This term is applied in a confined sense to the analysis or separation of the precious 
metals from other metals ; and to the determination of the quantity or value of gold and silver in bul- 
lion, coin, plate or trinkets, but more generally to the operation which decides the quantity of a certain 
kind of metal contained in an ore, or in an alloy, if it is performed by heat chiefly, in conrradistinctioB 
to analysis, or the operation by moisture. 

ATMOMETER. An instrument for determining the rate of evaporation from a humid surface. 

ATMOSPHERE; that gaseous fluid which surrouuds the earth, according to Dr. Prout, 100 cubic 
inches of which composes the atmosphere at the surface of the earth, when the barometer stands at 3(1 
inches, and at a temperature of 60 Fahrenheit, weighs 31.0117 grains, being thus about 815 times lightev 
than water, and 11,005 times lighter than mercury. Since the air of the atmosphere is possessed of 
weight, it must he evident, that a cubic foot of air at the surface of the earth, has to support the weight 
of all the air directly above it, and that therefore the higher we ascend up in the atmosphere, the lighter 
will be the cubic foot of air ; or in other words, the farther from the surface of the earth, the less will 
be the density of the air. At the height of three and a half miles, it was found that the atmospheric 
air was only half as dense as it was at the surface of the earth. From the nature of fluids, it follows, 
that the air of the atmosphere presses against any body which comes into contact with it ; because 
fluids exert pressure in all directions, upwards, downwards, sidewise, and oblique. From the nature of 
fluids it also follows, that the pressure on any point is equal to the weight of all the particles of the fluid in 
a perpendicular line between the point in contact, and the surface of the fluid. The amount of pressure 
of a column of air, whose base is one square foot, and altitude the height of the atmosphere, has been 
found to be 215G pounds avoirdupois, or very nearly 15 pounds of pressure on every square inch. It is 
common to state the pressure of the atmosphere as equal to 15 lbs. ou the square inch. If any gaseous 
body or vapor, such as steam, exert a pressure equivalent to 15 lbs. on the square inch, then the force 
of that vapor is said to be equal to one atmosphere ; if the vapor be equal to 30 pounds on every square 
inch, then it is equal to two atmospheres ; and so on, consequently, the atmospheric pressure is capable 
of supporting about thirty inches of mercury, or a column of water 3-1 feet high. It is found that the 
pressure of the atmosphere is not constant eveu at the same place ; at the equator, the pressure is nearly 
constant, but it is subject to greater change in the high latitudes. In this country the pressure of the 
atmosphere varies so much, as to support a column of mercury sometimes so low as 28 inches, and at 
other times so high as 31, the mean being 29'5. This would make the average pressure between 11 and 
15 pounds on the square inch. In scientific books generally, the pressure is understood in round num- 
bers to be 15 lbs., so that a pressure exerted equal to one, two, three, four, &c. atmospheres, means such 
a pressure as would support 30, 60, 90, 120, &c. inches of mercury in a perpendicular column, or 15, 30 
■15, 60, &c. pounds on every square inch. 



ATMOSPHERIC ENGINE. See Caloric Engine. 

ATMOSPHERIC PRESSURE, applied to pile driving by Dr. Pott's system. Atmospheric pressure 
has been applied to the erection of several beacons in the vicinity of the mouth of the Thames. The 
first experiment was upon the Goodwin Sands on July 16, 1845, and an iron tube of 2 feet 6 inches 
diameter was driven into the sand to a depth of 22 feet in two or three hours. A gentleman, present 
at the experiment, which was made by the Trinity Brethren, said, that the facility with which this 
large iron tube was made to descend could be compared to nothing better than shutting up a telescope. 
The method of operation is this : the tubes are in convenient lengths, with spigot and faucet joints, and 
one of them being placed perpendicularly, an air-tight cap is fixed to the upper end. This cap com- 
municates with a powerful air-pump, by means of which the air is exhausted from the tube, drawing 
up the sand or shingle with the water which ascends, and the tube immediately descends from the ef- 
fects of outward atmospheric pressure. The contents of the tube are then removed by the pump, 
which readily draws away the sand or shingle with the water which rises during their action, and the 
exhaustion process is then continued. The upper end of the tube having become level with the surface, 
the operation is stopped, the cap removed, a fresh rube is affixed and secured, and the same course pur- 
sued, and thus continued, until, with the greatest facility, this great length of tube penetrated what 
must have been exceedinsjlv hard sand. 


ATTRACTION. A tendency which certain bodies have to approach and adhere to each other. 
There are several kinds of attraction, as of gravitation, cohesion, capillarv, chemical, electrical, &c. 

ATWOOD'S MACHINE. See Acceleration. 

AUGERS. See Boring Tools. 

AUGER. Invented by AVm. Ash. An instrument to produce holes of various diameters, with the cut- 
ting and guiding parts detached, so as to change them at pleasure 

Figs. 198, 199, 200, and 201, represent the auger in 
three different positions. Fig. 201 shows its end. A is the 
spindle ; B the conical screw ; C the worm fitted on the 
spindle. The upper end of the worm is made to bear 
against the stop D. F is the cutter fitted into a mortise 
in the spindle, fastened by the wedge-piece G. The cut- 
ter F, is shown above in four detached positions, Fig. 202. 
The lower end of the worm bears against the back of the 
cutter, and the wedge G rests also in a small notch cut in 
the face of the worm, as seen in Fig. 200. On taking out 
the wedge the cutter can be taken out, and also the worm, 
when another worm or cutter of a different size may be at- 
tached to the spindle. In this way the cutter can be taken 
out and sharpened at pleasure. Instead of the worm C, 
the guides, Figs. 203 and 204, are sometimes substituted. 
Fig. 203 is a vertical, and Fig. 204 a horizontal, section. 
This guide consists of a ring, K K, having a slightly conical 
screw-thread on the outside, from which extend two 
wings, 1 1, supporting a thimble, L. Through this thimble 
the spindle A passes, and the cutter being applied to bore 
the wood, the opening of the hole is only to be cut in the 
first place, then the ring of the guide is firmly screwed 
into that orifice ; and in boring, the cutter will then be 
directed by the spindle sliding through the thimble. By 
the worm the chips are carried up out of the hole. By 
the guide the chips will rise through the opening K and 
the thimble L. The worm appears to be, by far, the best 

AUGERS, machinery for making. The object of the 
inventor, Mr. Palmer, is to manufacture the " single-twist" 
auger, usually made of a rod of metal, twisted round a 
cylinder into a helical curve. The auger which the inven- 
tor's machinery is intended to manufacture, is formed 
of a long rod of metal, (either of a triangular or other prop- 
er shape, in its cross-sectiou) The iron should be rolled 
in square bars or rods, of the size required, and be cut 
into pieces of sufficient length, to make the tool or instru- 
ment intended. A small piece of steel of proper size for 
the cutting-lip, and the conical screw, if it is to be added, 
is next welded upon one end of each one of the pieces, 
and the end is next turned or bent down at right angles to 
the remainder, upon an anvil, so as to fit into the cavity of 
the lower section of the dies, for forming the lip, or the lip and screw cone. About three-fourths of the 
length of the rod from the steel knob is next heated to the necessary temperature, to be rolled down by 
the next portion of the machinery. The next portion of the process of manufacturing the au^er, consists 
in forming the cutting-lip, or the cutting-lip and conical screw-blank, upon its end. For this purpose, 
dies are employed to form the Up without the conic blank. The head of steel being heated, is placed 
between the dies, and the upper of them caused to descend, with the force necessary to swedge or 
compress the metal into the shape required. The knob thus formed, is next bent down to the angle re- 


quired to be applied to the machine, by which the rod is twisted in the helical curve. The next operation 
is to °-ive the requisite degree of uniformity to the size and spread of the twist, which is accomplished by 
hammering in the machine, consisting of a trip-hammer, arranged and operated over a die-anvil or bed- 
piece, grooved out, so as to receive the twisted helix when laid thereon. By turning the auger around, 
first in one direction and next in the opposite, successively, so as to cause it to pass back and forth be- 
tween the hammer and bed-piece or anvil, the twist is spread out in a uniform manner. The lower 
part of the hammer should be curved to correspond with the circumference of the exterior of the twist 
of the aui-er. The twisted portion of the auger is again heated, and rolled between heavy iron plates, 
for the purpose of straightening the twist ; during which operation care should be taken that the cut- 
tine lip of the anger does not come in contact with the plates. The auger is next to be finished by 
filino-, and upon grinding and polishing wheels, or by other proper means, in such manner as may be 
desirable ; and when a screw is to be connected with the cutting-lip, it may be cut upon the blank by 
any contrivance adapted to the purpose. 

197. Various machines are used to hold the auger in the 

required position whilst boring, of which the most 
common is that used by house carpenters for keeping 
the tool perpendicular to the face of the work. The 
foot of the frame rests upon the timber, and guides 
hold the auger at right angles to it : motion is con- 
i veyed through bevel geers and a crank. For ship car- 
penter's use, the following cut represents a frame in- 
vented by Richard Coffin, of Haverhill. 

A is the foot. D is the frame. C is a rod and 
crank attached to the auger H. B is the cup and 
head. E is the spring. G G are two rods for the pur- 
pose of disconnecting the catches F F from the rod C. 
If you wish to bore, pull the spring E by the handle 
to the left ; shove down the left-hand rod G, to discon- 
nect the left-hand catch from the rod C. The right 
hand catch holds the spring, and throws its power to- 
wards the auger H, and so on ; the cup B allows its 
ball to roll in the auger and frame in any position, and 
the thumb-screw will hold it in that position ; the other thumb-screw is to hold the slide whioh ele- 
vates or depresses the auger. 

AUGERS, double and single twist, of Sandford, Newton and Smith of Meriden, Conn. Constructed 
with a uniformly decreasing length of twist, with a corresponding gradual tapering of the cavity of the 
auger, from the shank to the lower or cutting extremity. Any person skilled in the art of making au- 
gers can form the graduated double-twist with tongs and hammers, in the ordinary mode of twisting 
double-twist augers, by exercising due care and attention. A better method is to have the dies in what 
auger manufacturers call crimp-jaws, so constructed as to conform in size, graduated length of twist, 
and taper of the cavity, to the proposed auger. The auger having been first twisted by the common 
method, with the tongs and other tools, to about the shortness of a medium in the proposed twist, is, 
while hot, put into the crimps, which are then brought suddenly together by the usual process, the au- 
ger being at the same time turned partially round, backward and forward. The twist is thus made of 
a gradually increasing length, with a corresponding gradual enlarging cavity from the lower or cutting 
end to the other extremity of the twist. 

To form single-twist augers with this improvement, that part of the rod which is to form the twist, 
should, before being twisted, be drawn with a graduated taper from the part which is to form the shank, 
to that which is to form the lower or cutting end. The auger may then be twisted in the usual way, 
by having the mould upon which it is formed or twisted, made to conform in size, graduated length of 
twist, and taper of cavity, to the proposed auger. The mould is a machine well known to all makers 
of single-twist augers. 

The superiority of augers made with this improvement consists, in that the clogging of the chips or 
core in the twist, while in the process of boring, is effectually prevented ; thereby materially diminish- 
ing the friction. And also, that the shortness of the twist at the lower end gives a better opportunity 
to finish the cutting-lips, so that they may bore more smoothly and evenly than when the auger is made 
in the ordinary way, with a slack or open twist. 

What the inventors claim as their improvement and invention, is the making or constructing dou- 
ble or single twist augers, with a gradually increasing length of twist, and the consequent gradual en- 
largement of cavity from the lower or cutting end to the other extremity of the twist. 

AUGER, double-lipped, convex and concave. Improvement in the form and construction of concave 
screw-augers, by N. C. Sandford, Meriden, Conn. This improvement consists as follows : Instead of 
having the plate, from which the auger is to be twisted, of concave shape throughout, as is usual in 
forming concave augers, the lower extremity of the plate is of convex shape, or of even thickness, 
though the former is preferred. In augers of five-eighths diameter it will be sufficient to have about 
one inch of the lower extremity of convex shape, or of even thickness, as aforesaid, varying in propor- 
tion as the diameter of the auger is increased or diminished. 

The advantage of this mode of construction consists in, that the workman, when twisting the auger, 
which is done in the ordinary mode, is better enabled to give to the plate a short twist at the lower ex- 
tremity, and finish the cutting-lips or edges in the best and most approved method for easy boring, thaD 
when the plate is formed in the usual way, of concave shape throughout. 

_ What Mr. Sandford claims as his invention, is the forming of the lower part of the plate of a convex 
ihape, or of even thickness, when this is combined with the upper part of the plate formed of a concave 



shape. The whole plate being formed for the purpose of making therefrom a double-lipped, convex, 
and concave auger. 

AUGER MACHIXE. This new and useful improvement in the mode of equalizing ana straigntemng 
the twist of double and single twist screw augers, invented by Sandford and Smith, of Meriden, Conn., 
may be described as follows : 

Set firmly in the ground, or otherwise secure to the floor, two posts, marked a, Fig. 208, about six 
feet apart and fifteen inches in diameter, of sufficient length to elevate the machine to a convenient 

distance from the ground. Upon the upper surface of these posts is placed horizontally, and se- 
cured strongly, a piece of timber 6, say of oak, about twenty inches wide on its upper surface, and four 
inches thick. This we term the bed of the machine. Two straight cast-iron bars c, about two inches 
thick and two inches wide, of the same length as the bed, and raised about twelve inches therefrom, and 
theu placed about twelve inches apart, parallel to each other and to the bed. Each of these bars is 
secured to the bed by two vertical posts of iron, D. Fig. 20S shows the machine as thus far construct- 
ed. "We then take a piece of cast-iron, say two feet long, fourteen inches wide, and one inch thick, with 
its edges raised about one inch, so as to form a dovetail on its upper surface. This we call the 



lower stock, and is represented by that portion of Fig. 210 marked h. This stock is placed in th« 
centre of the bed, between the bars; screws passing through the bed and attached to the stock, 
serve to elevate or depress it at pleasure. Another screw, passing through the centre of the stock 
and through the bed, enables the operator to confine and hold the stock firmly on the first-named foul 

Another piece of cast-iron, of similar dimensions, but with the dovetail on its under surface, is then 
placed under the bars, so that about one inch of each edge of the upper surface of its entire length 
shall bear upon the under surface of the bars. This we term the upper stock, and is held to the 
bars by four hooks, marked g, in Fig. 209, attached to the upper surface of the stock, and resting in the 
upper surface of the bars, so as to admit a sliding movement of this upper stock. Tins movement is 
effected by means of a rack c, and pinion ; the rack, to be of sufficient strength, should be formed of 
a cast-iron bar, about two inches square, and of the same length as the bars, with cogs about two nich- 
es in length, and is attached lengthwise to the surface of the upper stock. The pinions and shaft 
should be of corresponding dimensions ; and being turned by means of a crank or wrench, give an 
alternate backward or forward movement to the upper stock. Fig. 209 represents the machine with 
the upper stock k, and the lower stock h, in their respective places, and the rack e, and pinion at- 
tached. There are then inserted into these stocks, metallic plates, or dies, of about one inch thickness, 
which fit into and are securely held by the dovetails above mentioned. To each of these plates, or 
dies, are secured, by means of rivets or screws, two wales of cast-steel, running parallel to each other 
in an angular direction across the plates. Fig. 210 shows one of these plates i, partially inserted in the 
stock h. When the plates are separated from then- respective stocks, the wales upon the plate are designed 
for the lower stock, and vice versa ; so that when the plates are inserted in their respective stocks, 
the wales upon the upper plate run in an opposite direction from those upon the lower plate, form- 
ing an angle with each other. The size of the wales will depend upon the size of the auger to be 
formed ; and the angle at which they cross the plate must be governed by the openness or closeness 
of the proposed twist, so that separate plates, adapted to each size of auger respectively, will be re- 

If it is desired to form the auger so as to make the graduated twist, it may be effected by slightly 
curving and also tapering, as shown in Fig. 212, the wales; increasing or diminishing the curve and 
taper, in proportion to the degree of graduation contemplated. 

The plates are adjusted at the proper distance from each other, required by the size of the augtr to 
be formed, by means of the screws. 

To work the machine the crank is turned backward, so as to move the upper plate directly over 
the opposite extremity of the wales upon the lower plate, as shown in Fig. 211. The machine is then 
ready for operation. The auger being twisted by hand in the usual way, (which can be done with 
great expedition, as particular nicety in this respect is rendered unnecessary by the use of the ma- 
chine,) is placed while hot in the machine, with the part nearest the shank on the wales, which being 
adapted to the size of the auger to be operated upon, will fill the cavity of the twist. The upper 
plate is then moved forward by turning the crank, and rolls the twist part of the auger between the 
plates, these giving it an exact ana uniform size ; while, at the same time, the wales operate upon 
the cavities of the twist, opening or closing them as may be necessary, and by a single forward move 



ment of the machine, produces a perfectly even and regular twist. Thus forming a better article, and 
at less expense, than can be done by any method now in use. 

Messrs. Sandford and Smith, claim the raising upon and securing to the surface of level metal- 
lic, or other plates composed of hard substance, wales running either in straight or curved lines, and 
operated substantially in the manner just specified, for the purpose of forming the twist of double and 
single twist screw augers. 

AUTOMATIC DIVIDING MACHINE, arranged for use in the Coast Survey Office, by Joseph Sax- 
to.v, assistant in the office of weights and measures, Washington, and constructed by William Wurdeman, 
mechanician, coast-survey office. — The dividing machine, which has been rendered automatic by Mr. Sax- 
ton, was imported for use in the coast-survey office, by the late F. R. Hassler, Esq., superintendent. The 
graduations made by means of it, by different persons, were unsatisfactory. Many causes were assigna- 
ble for this, and it was considered by the present superintendent, Professor A. D. Bache, desirable that 
the most obvious of the causes of 
error should be got rid of, by render- 
ing the machine automatic, before the 
minor causes of irregularity were 
sought for. This was done by Mr. 
Saxton, in the manner described in 
the following pages. The result has 
been very successful, not only in its 
first application, but in permitting 
the determination and removal of 
sources of error, previously conceal- 
ed in the working of the machine. 
The drawings of the proposed ad- 
ditions upon a scale necessary for 
working, were made by Mr. Saxton, 
and the work was executed by Mr. 
William Wurdeman and his assist- 
ant mechanicians in the coast-survey 
office. Accuracy, beauty of finish, 
ease of reading, economy of time, 
and labor in dividing, have all been 
gained" by the improvements. 

The machinery for rendering the 
dividing machine automatic, consists 
of a brass wheel A, about 20 inches in 
diameter, mounted on the axis B, Fig. 
213. One of the arms of the wheel A 
has a slit extending from near the cen- 
tre of the rim ; in this slit is fixed the 
crank-pin so that it can be placed at any re- 
quired distance from the centre. On the edge 
of the wheel is turned a groove, in which runs 
a cord for driving the wheel. On the other 
end of the axis is fixed the wheel C, which is 
geared into the wheel D, on the lower end of 
the vertical shaft E, Fig. 214. On the upper 
end of the same shaft, is another wheel F, 
geared into the wheel G, on the horizontal 
shaft H. On the end of the shaft H, is a wheel 
I, which gears into the wheel J, on the axis K. 
The wheels C D F G I and J are all bevel 
wheels, having the same number of teeth, (60 ) 
and work into each other at right angles. 

The shaft E has on it a shding-joint L, for 
altering its length ; the shaft H is turned and 
ground of uniform thickness, so that it may 
slide accurately through Hie socket of the 
wheel G, and also through its bearing at M, in 
which it turns. The axis K has on it two ec- 
centrics, N and : If to raise the tracing point, 
and to move it horizontally. One-half of the 
circumference of If is concentric with the axis 
on which it turns, so as to keep the point up 
while the crank- wheel moves half a revolution, 
and is moving the dividing plate. The other 
is eccentric to the axis about one-tenth of 
an inch, so as to let the point rest on the circle 
while it is making the division. The eccentric 

has about Jth of its circumference concentric to the axis ; the rest is described from a point about J r th oi 
an inch from the centre. N and must be fixed on the axis with regard to each other, so that N will raise 
the point before begins to move it back, and both with regard to the crank-wheel A, so that the point 


will be raised before the crank begins to move the dividing plate, and keep it up until it is done moving, 
and has moved the point back, and then let it down before begins to let it return. The axis K has 
also on it, near the end, a small cog P, to sliift the ratchet-wheel Q one tooth every revolution of K. The 
ratchet-wheel has 60 teeth, and is kept in its proper position by the detent spring R. In front of the 
wheel, and fastened to it by two screws, is a circular plate S, Figs. 213 and 215, with 20 notches in its 
ed^e, the deepest one for the longest line, or 5° ; the next for 30' ; and the shallowest for 15' ; and the 
edge of the plate for the 5' lines. 

The segment T, Figs. 213 and 215, is fixed on the vertical part of the tracing-frame U, and has a pin 
in the end at V, of such a size that it can drop into the notches in S, as they are brought under it by the 
revolutions of the ratchet-wheel, and so rpgulate the length of the division lines. The time of raising the 
ratchet must be when the stop-pin is raised out of the notch, by the motion of the traces backwards. 
To give motion to the screw, a stout fusee-chain is used, one-eighth of an inch broad, and one-fourteenth 
of an inch thick, which answers well ; one end is attached to the ratchet-barrel W, round which it is 
wound five or six turns ; the other end is attached to the crank-pin X. Near the lower end of the chain, 
at Y, is a small tube, containing a strong spiral spring, arranged like the common spring weighing-ma- 
chine, but having a motion of only about Jul of an inch ; the spring must be so strong as not to give by 
the force required to turn the screw, but only to give a little when the ratchet comes up to the stop, and 
the crank is just passing the lower centre. Between the spring and the crank-pin is an airangement for 
lengthening or shortening the chain, when it is arranged for making a larger or smaller division : for this 
purpose, two pieces of brass wire, about six inches long, having a screw cut on them their whole length. 
Ejid eacli filed away one-half, and two small milled nuts, tapped with the same thread, are run on each ; 
ine two wires are laid together, and the nuts screwed up until they embrace botli wires, as shown at Z, 
Fig. 213. 

The crank-pin is fixed on a slide, projecting beyond the nut which fastens it, so that it maybe extended, 
if necessary, beyond the circumference of the wheel, or by reversing, it may be brought quite to the 
centre. When the divisions are to have the long end towards the centre, a jointed lever, as shown at a. 
Fig. 215, is used. It is screwed fast to the cross-bar b, Figs. 214 and 215, directly over the eccentric 0, 
and connected to the vertical framo U at c, and the stop-pin V is shifted to the other end of T, and the 
abutting piece / on U, is to be removed, when the eccentric will act against the lever a, at d, and 
move the point in an opposite direction. The tracing-frame is made to follow the eccentric, by a weight 
and cord passing over a pulley and honked to the vertical part of the tracing frame at ee, Fig. 215. 

When the adjustment is made for dividing with the long end of the division lines, towards the circum- 
ference of the circle, all the wheels connecting the axis K with the axis B should be marked with a dot 
on the tooth and space in winch it works, and a line should be drawn on the shafts E and H, and a cor- 
responding mark on the sockets through which they pass, so that they may always be fastened in the 
same position. The axis K should have two short pins fastened on it, and notches in the ends of the 
bogeys If and 0, to fix them in their proper position when the lines are towards the circumference or 
centra, as the case may require. The slit in the crank-wheel A, in which the crank-pin is fastened, should 
also be graduated, showing the distance of the pin from the centre, for each degree, minute, and second 
that may be required in dividing. 

By marking the position of each part of the macliine in this way, much time and trouble will be saved 
in making the necessary changes for different kinds of dividing, whether it be in the number, or the di- 
rection in which the long lines are to be extended. The tracing point should be adjusted so as not to 
be raised more than about the thirtieth of an inch, or it will be liable, in descending, to make a small dot 
at the commencement of each line, which woidd injure the appearance. In the drawing, the eccentric 
N is represented as acting on the tad of the tracing-frame, but it is better to make it act on a steel pin 
in the side of the tail. 

By this arrangement of the crank for turning the dividing-screw, the stops of the ratchet are brought 
in contact when the crank is passing its centres, and the motion of the screw is so slow, that it is not pos- 
sible for the stops to strike so hard as to do any injury, and the dividing may be done with great ra- 

AWLS. See Boring Tools. 

AXLE. A shaft supporting a wheel ; the wheel may run on the axle, or be fastened to it, and the 
axle turn on bearings. For size and form of mill axles or shafts, see Geering. 

ON THE FORM OF RAILWAY AXLES. A very extensive course of experiments has been 
gone through by Mr. Thorneycroft, approximating as closely as possible to the forces on axles when in 
use, with a view to ascertain the best form to be given to axles, to enable them to resist fracture or de- 
flection. The railway axle is viewed as having certain relations to a girder in principle. Girders gene- 
rally have their two ends resting on two points of support, and the load is either located at fixed distances 
from the props, or dispersed over the whole surface ; of the axle the wheels may be considered the 
props, and the journals the loaded parts. It is found that the inclined surface of the wheel tire given 
by coneing, ranges from 1 in 12 to 1 in 20, and, as a matter of course, the direct tendency of the wheels 
uuderaloadis to descend that incline, so that every vertical blow which the wheels may receive is 
compounded of two forces, viz : the one to crash the wheels in the direction of their vertical plane, and 
the other to move the lower parts of the wheels together ; it will be seen that these two forces have a 
direct tendency to bend the axle somewhere between the wheels. 

An axle reduced in the middle to 1 J inch diameter, was placed upon two props 4 feet 9 inches apart, 
and loaded in the middle, the utmost of its deflection without a permanent set, was .232 inches, the 
load carried 7 tons. An axle reduced to 4 inches in the middle, and then placed upon the props 4 feet 
9 inches apart, its utmost deflection without a permanent set was .281 inches, the load carried 9 tons. 
Another axle, but parallel 4 j 5 6 inches diameter, was placed upon the props 4 feet 9 inches apart, its ut- 
most deflection without a permanent set, was .343 inches, the load carried 14 tons. Hence by reducing 
an axle of 4 £ inches diameter in the middle to 3f inches, its limit of elasticity is reduced from .343 


inches to .232 inches, and the load, to produce that elasticity, from 14 to 7 tons. Fig.216, shows tfcfl 
position of the wheels to the rails when the bending of the axle has exceeded its elastic limit. 





E raf 



To ascertain what influence the reduction of an axle in the middle would have on its strength to re- 
sist sudden impact, compared to an unreduced one, an axle was made as represented by fig.217, which 
shows the end A, parallel to the centre, \\ inches diameter, and the end B is drawn down from the back 
of the wheel towards the centre, where it is 4 inches diameter. The end A was then subjected to impact 
— the relative position of the prop and ram was the back of the wheel and the neck of the journal, this 
end received 46 blows of the ram, and bent to an angle of 18°. The end B was then subjected to im- 
pact — the prop and the ram in the same relative position, when it bent back to an angle of 22 = with 
only 16 blows of the ram (as shown by the clotted lines in fig.217. The object of the third experiment 
was to ascertain what influence a shoulder behind the wheel would have on the strength of the axle at 
that part, compared to one without a shoulder. Figs. 218,219, were one axle cut in two, and the end E 
was turned from the neck of the journal, leaving a shoulder \W\ inch deep, as a stop to the wheel; the 
end F was turned from the neck of the journal to the same diameter, but no shoulder left. The end E 
was subjected to hydraulic pressure, the load being in a direct line with the shoulder, when it broke in 
two with a load of 60 tons. The end F was subjected in the same way to hydraulic pressure, when it 
bent into the form shown by the dotted lines, with S4 tons. To ascertain what influence the position 
of the wheel, in relation to the neck of the journal, would have on the strength of the journal nnder 
impact, fig.220, a piece of an axle with a journal taken down at each end was used ; the end G was 

220. ,-, ,-, keyed into a cast-irou frame, the face of the frame in a 

line with the neck of the journal, the journal was then 
subjected to the impact of a ram, falling 10 feet, when 
it broke off at the seventh blow. The end H was keyed 
into the cast-iron frame in the same way, but with the 
neck of the journal projecting 1^- inch from the face 
of the frame, the journal was then subjected to the impact of the same ram falling 10 feet, when it 
broke at the 24th blow. 

From these experiments it is obvious that neither shafts nor railway axles ought to be reduced in the 
middle, but rather, if there is to be a departure from the parallel form, they should be made thickest in 
the middle, and thus effectually prevent any vibration or bending whatever. 

Railway axles are mostly made solid, those drawn 
nnder the hammer being better and safer than 
those that are rolled. Fig.221, represents the section 
of a fagoted axle, as constructed by the Brunswick 
Iron works, England ; * the segments show the forms 
of the pile composing the axle. Fig.222, is a section 
of a hollow axle as constructed at the same works. 
Fig.223, apian of the same axle with a portion taken 
off showing the cavity. 

The selection of the tubular form of axle origi- 
nated from the knowledge that, with a considerably 
less weight of material in the form of the tube, a 
much greater strength can be obtained to resist 
torsion, deflection by pressure or weight, or concus- 
sion from blows. The use of hollow axles was 
tried some years ago, but was not continued, the 
main objection being that there appeared a great 
difficulty of insuring, by the particular mode of 
manufacture adopted at that time, a sufficient uni- 
formity of thickness of the sides of the tube through 
out, and also of the soundness of material. Since 
then a mode of manufacturing hollow railway 
axles has been introduced, which, it is believed, se- 
cures the utmost strength with the least possible amount of material, uniformity of structure of the 
>on, perfect equality of thickness of material, and soundness of manufacture. 
The plan adopted is as follows : A number of segmental bars of the best quality of iron are rolled U 
* Geo. TT. Billings agent, 66 Broadway, New York. 



a section, so as to form, when put together ready for welding, a complete cylinder about 1+ times th« 
diameter of the axle when finished, the bars fitting correctly together, so as to have no interstices, an* 3 
overlapping in such a manner as to insure a perfect and sound weld when completed. 

This cylinder of loose segmental bars is temporarily hel£ together by a screw-clip, and each end be- 
ing put into the furnace until a welding heat is produced, the bars are then partially welded together, 
and the clip removed. The whole cylinder is then placed in the furnace and brought to a proper weld- 
ing heat : it is then passed through a series of rollers, B B, fig.224, which have each a mandril of an egg 
form A, in the centre of the circular opening, which is attached and supported on the end of a fixed 
bar, the bar beiug firmly secured at the opposite end to resist the end pressure of strain during the pro- 
ces3 of rolling. The mandrils are made of cast-iron, chilled, fitting on like a socket on the end of tho 
bar to a shoulder, aud they are secured by a screw-nut, so that they are easily removed when required. 

The motion of the rolls is so arranged by a reversing clutch on the shaft, that as soon as the axle 
cylinder has been drawn clear through, the motion is reversed, and the axle which has been drawn on 
the mandril-rod, is again drawn back through the same openings in the rolls; it is immediately passed 
through the next smaller groove of the roll, with a decreased size of mandril, and again reversed back 
through the same groove in a similar manner, and so on through a series of grooves in quick succes- 
sion, each decreasing in size, and consequently increasing the compression and strength of the iron oi 
which the axle is formed ; and by the last groove it is passed through, it is reduced to the proper diam- 
eter. At each time it is changed from one groove to another, the axle cylinder is turned by the work- 
men a quarter round, so as to equalize the pressure on every part of the surface, to insure uniformity 
of the compression of the iron, and thoroughly complete a sound welding throughout every part of the 
axle. The axle, after being welded and drawn down in the rolls to the proper size, is taken at once to a 
hammer, where it is planished between semicircular swages over its entire surface. A small jet of 
water plays upon it during this process, which enables the workmen to detect at once, by the inequality 
of color, any unsoundness in the welding. From the hammer it is taken to the circular saws, where it 
is cut accurately to the length required, and ready to have the bearing formed upon it. The ends are re- 
heated, and gradually drawn down by a hammer to the proper dimensions and form of the journals, a 
mandril being inserted in the end of the tube during the process of hammering. 

The weight of two axles of the solid description finished is, say 5 cwt., and if replaced with hollow 
axles of equal strength, the weight may be reduced li cwt. Two different kinds of bearings are used, 
the parallel bearing with the rounded shoulder, aud also the double conical bearing. In either descrip- 
tion of bearing the hollow axle is good, although it is believed that the conical bearing for either tho 
solid or hollow axle has less tendency to injure the texture of the iron during the formation of the jour- 
nal than the parallel shouldered axle. 

The experiments on transverse strength by a heavy weight falling on the centre of the axle, and giv- 
ing the blow on opposite sides alternately, show that the hollow axle is nearly double the strength in 
that respect of the corresponding solid axle, the amount of bending being only 5 inches instead of 9| 
inches ; and the number of blows required to break the hollow axle being 29, whilst the solid axle 
broke at the fifth blow, shows the hollow axle to be greatly stronger in resistance to fracture. The ex- 
periments on strength of journals show that, instead of the journals breaking off square aud short ai 
the shoulder, as in the solid axles, the hollow axle journal stands a considerably greater number of 
blows, and then only splits up longitudinally, instead of breaking off transversely, being a very impor- 
tant advantage in point of safety iu working. 


BACKING. In masonry, the filling in behind the face of the wall. 

BACK-LINKS. The links in a parallel motion -which connect the air-pump rod to the beam. 

BACKWATER. Water in the race of a mill, and rising above the bottom of the wheel. 

BAKING. See Bread. 

BALANCE, as applied to machinery, refers to parts in equipoise, as balance Docks, Gates, Valves t 
which, See. 

BALANCE. A well known modification of the first order of levers, commonly called the beam and 
scales. See Scales. 

BALLASTING. A term applied to the covering of roads generally, and to the filling-in material, 
above, below, and between the several stone blocks and sleepers upon railways, &c. ; it is laid for the 
purpose of keeping the road dry, as in the event of water lying upon it, the rails invariably sink, as it 
causes them to rest unequally. Ballasting is composed of gravel, broken stone, or the like, and is laid 
about two feet thick on railways, and it is generally from 6 to 12 inches thick on roads. 


BALKS. Long pieces of timber. 

BALUSTERS. Small columns or rods capped by a rail 

BAR. A piece of timber or metal placed horizontally, aud running across from one part of any 
framework to another. 

BAR, (in navigation.) An accumulation of sand or shingle at the commencement or mouths of rivers, 
harbors, &c, being formed by the action of the tides. 

BARBERY-WOOD. See Woods, varieties of. 

BAROMETER. An instrument used for observing the pressure and elasticity, or variations in den- 
sity of the atmosphere. It is commonly employed for the purpose of determining approaching 
variations in the weather; and more scientifically for measuring altitudes. There are various modifica- 
tions of the barometer, as the LMagonal, Horizontal, Marine, Pendant, Reduced, and Wheel Barometer; 
in all of which the principle of construction is the same — the only difference being in its application. 

The essential part of a barometer is a well-formed glass tube, closed at one end, perfectly clear and 
free from flaws, 33 or 34 inches long, of equal bore, filled with pure mercury, and inverted, the open 
end being inserted in a cup partly filled with the same metal, so that the mercury in the tube may 
be supported- by atmospheric pressure. 

The vacant space between the top of the mercury and the top of the tube is called the Torricellian 
Vacuum, in honor of the inventor of the instrument. 

On pouring mercury into the barometer- tube and inverting it, the air thus confined between the 
mercury and the inner surface of the tube, will escape into the Torricellian vacuum. In order to get rid 
of this air, as well as moisture, the tube is first gently warmed, so as to diy it thoroughly. A quantity of 
pure mercury is then poured in, so as to occupy two or three inches of the sealed end of the tube, 
which is held over the fire until the mercury boils, taking care to turn the tube round upon its axis, 
so that the heat may be equally applied. After boiling for a minute or two, the open end is closed by 
a cork to prevent the introduction of moist air, and the tube is then allowed to cool, in order that the 
cooled mercury which is next to be poured in may not crack the tube. When a second portion of 
mercury, about equal to the first, has been poured in, the part of the tube containing this new portion 
is held over the fire until it boils. It is again removed from the fire, and corked up as before. A third 
portion of mercury is then introduced, and the heat again applied to that part of the tube contain- 
ing the last addition of metal ; and in this way the tube is at length filled, with the exception of a 
small portion from which the mercury ha& been expelled by the heat. This is filled up with mercury, 
and the finger is now placed over the opened end so as carefully to exclude any air ; the tube is tben 
reversed into a cup of pure mercury ; as the column sinks, it expels the last portion of mercury which 
had not been boiled ; and as there is neither air nor aqueous vapour above the mercurial column, its 
length exactly measures the atmospheric pressure. A film of air is always retained on the outside of 
the tube, and also at its under edges, which film creeps by small portions at a time into the interior, and 
rises up in innumerable bubbles into the vacuum, the film being constantly renewed by the descent of 
more air between the outside of the tube and the mercury in the cup, and thus the outer air slowly in- 
sinuates itself into the barometer. In this way the most carefully constructed barometers have be- 
come deteriorated in the course of years. 

This irregular and uncertain deterioration of barometers was remedied by Professor Darnell, by 
uniting a ring of platinum with the open end of the barometer-tube, so as to bring it into contact with 
the mercury, thus effectually preventing the ingress of air into the tube. 

The same philosopher also invented a new mode of filling barometer-tubes, by pouring the mercury 
into the tube while both are under the exhausted receiver of a good air-pump. The mercury is poured 
through a long slender funnel extending to the bottom of the tube, and dipping into a small portion of 
mercury previously introduced, and boiled. By this means all agitation is confined to the tube of the 
funnel, and the tube left perfectly free of air. The mercury was afterwards boiled in vacuo. 

The excellence of the barometer chiefly depends on the absence of all matter except mercury from 
the tube, and its value may be tested by three indications: — First, by the b lightness of the mercurial 
column, and the absence of any flaw, speck or dulness of surface; secondly, by the barometric light, as it 
is called, or flashes of electric light in the Torricellian vacuum, produced by the friction of the mercury 
against the glass, when the column is made to oscillate through an inch or two in the dark ; thirdly, by 
a peculiar clicking sound, produced when the mercury is made to strike the top of the tube. If air 
be present in the tube, it will form a cushion at the top, and prevent, or greatly modify, this click. 

The sectional area of the tube is of no consequence, as the atmosphere presses with the same intensi- 
ty upon the surface of the mercury in the cup, the column suspended in the tube will be of the saina 
height, whatever its internal diameter. 


The heidit of the mercurial column must he measured from the surface of the mercury in the cis- 
tern. When the atmospheric pressure increases, and the mercury in the tube rises, a portion of the 
metal is drawn out of the cistern into the tube, and the level of the mercury in the cistern is depressed 
so, on the contrary, when the atmospheric pressure diminishes, a quantity of mercury is forced out of 
the rube into the cistern, and the level of the metal in the latter rises. 

In some instruments the scale, accurately divided into inches and parts of inches, is made movable, 
and terminates in an ivory point, which is brought down to the surface of the mercury. When this 
point and its reflection appear to be in cmtact, the height indicated by the scale is correct. In other 
forms of the barometer, the mercury in the cistern is always maintained at the same level, for which 
purpose the cistern is formed partly of leather, so that, by means of a screw at the bottom, the surface 
of the mercury may always be adjusted to the neutral point before taking an observation. The divi- 
sions of the scale usually begin at the 27th inch, and are continued to the 31st. But in instruments 
intended to measure the height of mountains, or for accompanying balloons, the scale begins at the 
12th or 15th inch. Each inch is divided into ten parts, and these are subdivided into hundredths by means 
of a small sliding scale, called a vernier or nonius. 

The words " Change," " Fair," and " Rain " engraved on the plate of the barometer, are calculated 
to mislead ; in winter a fine bright day will succeed a stormy night, the mercury ranging as low a« 
29 inches, or opposite to ( Rain.* It is not so much the absolute height as the actual rising and fallinc 
of the mercury, which determines the kind of weather likely to follow. 

The barometer ought to he fixed in a truly vertical position, and if possible with a northern aspect, 
in order that it be subject to as few changes of temperature as possible. It is usual, for the sake of 
comparison, to reduce the observations to 32 s , for which purpose tables for correction for temperature 
are given in scientific works devoted to the subject of the barometer. The height of the cistern of 
the barometer above the level of the sea, and, if possible, the difference of the height of the mercury 
with some standard, should be ascertained, in order that the observations made with it should be com- 
parative with others made in different parts of tho country. Before taking an observation, the instru- 
ment should be gently tapped, to prevent any adhesion of the mercury to the tube ; the gauge should 
be adjusted to the surface-line of the cistern, and the index of the vernier brought level with the top 
of the mercury. 

Various contrivances have been made for increasing the length of the scale, or for making it more 
convenient for 'use. The most popular form is the common wheel-barometer, as it is called. In this 
instrument, the tube, instead of terminating at the bottom in a cistern, is recurved so as to form an 
inverted siphon. As a rise of the mercury in the longer or closed limb is equivalent to a fall in the 
shorter limb, and vice versa, a float is placed on the surface of the mercury in the shorter limb, and is 
connected with a string passing over a pulley, and very nearly balanced by another weight on the other 
side of the pulley. An index hand attached to the pulley moves over the surface of a dial-plate, gra- 
duated so as to indicate the oscillations of the mercurial column. With an increase of atmospheric 
pressure the mercury in the longer tube rises, and that in the short tube is depressed, together with the 
float, and this gives a small motion of revolution to the pulley, and also to the attached index hand. A 
fall in the longer column causes the mercury with its float in the short limb to rise, and consequently 
moves the index hand in the contrary direction. 

The measurement of heights was the first useful purpose to which the barometer was proposed to he 

Although the atmosphere may extend to the height of 45 miles, yet its lower half is so compressed 
as to occupy only 31 miles, so greatly do the upper portions expaud when relieved from pressure 
Hence at the ) g, mi] 7 ^ m mU 1± „ & 

height ot ) - ' i - ; j 

the elasticity of the! „ 

atmosphere is ) -' * ' s ' '« ' 

Halley was induced, by certain mathematical considerations, to fix upon the number 62,170 as a 
constant multiplier, and the rule for the measurement of heights may be stated as follows : — Observe 
the height of the barometer at the earth's surface, and then at the top of the mountain, or other ele- 
vated station ; take the logarithms of these numbers, and subtract the smaller from the greater ; mul- 
tiply the difference by 02,170, and the result is the height in English feet. This process gives a very 
near approximation, especially in temperate climates. 

But the progress of science soon rendered it evident that a correction for temperature was necessary 
in barometrical measurements, and a formula has been contrived to meet most of the difficulties of 
the question. The following rule will be found of easy application : — Multiply the difference of the 
logarithms of the two heights by the barometer, by 63,946 ; the result is the elevation in English 
feet. Then, in order to correct for temperature, take the mean of the temperature at the two eleva- 
tions ; if that be 89'6S° Fahr., no correction is necessary ; if above that quantity, add -j-5j-j>th to the 
whole height found for each degree above 69-68° ; if below, subtract the same quantity. For example : 
Humboldt found that at the level of the sea, near the foot of Chimborazo, the barometer stood at 
exactly 30 inches, while at the summit of the mountain it was only 14-85. The logarithm of 30 is 
1-4771213, and the logarithm of 14-85 is 1-1717237 ; then subtracting 


Multiply this by 63,946, which produces 19,539 for the elevation in feet. If the mean temperature of 
the two stations were 69-68°, no correction is necessary for temperature. This is a tolerably close ap 



proxirnation: the most careful calculation has given 19,332 for the real height, and this waa 
probably estimated for a lower temperature. 

A method has been given by Leslie for measuring heights without the use of logarithms. His rule 
is as follows : — Note the exact barometric pressure at the base and the summit of the elevation, 
and then make the following proportion : — As the sum of the two pressures is to their difference, so is 
the constant number 52,000 feet to the answer required in feet. Suppose for example the two pres- 
sures were 29-48 and 26-36 ; then 
As 29-48 + 26 36 : 29*48 — 2636 : : 52,000 feet: 2,905-4 feet, the answer required. 

This rule has been found applicable to the mean temperature of England for all heights under 
5,000 feet. 

Another method of obtaining approximate differences of altitude, is by a comparison of the tempera- 
tures of boiling water (which vary with the pressure of the atmosphere). 
The apparatus is exceedingly simple, and the instrument not so liable to 
injury as the mercurial barometer, being much more portable, and easily 
replaced. A. Common tin pot 9 inches high, by 2 in diameter. B. A 
sliding tube of tin, moved up and down in the pot ; the head of the tube 
is closed, but has a slit in it. C. to admit of a thermometer passing 
through a collar of cork, which shuts up the slit when the thermometer 
is placed. 

D. Thermometer with so much of the scale as may be desirable. 

E. Holes for the escape of steam. 
The boiling point for the level of the sea should be correctly marked 

by a number of careful observations, and the difference, if any, must be 
noted as an index error. 

These thermometers are very useful in ascertaining heights where 
strict accuracy is not required, and they have the advantage over mercu- 
rial barometers in being portable. In moderate elevations, the difference 
of one degree in the temperature at which water boils, indicates a change 
of level of about 500 Jeet, corresponding to a difference of 0-6 of an inch 
in a mercurial barometer. See Aneroid. 

BAR-WOOD. See Woods, varieties of. 

BARREL, (of a drum-wheel.) The cylindrical body or axle round 
which the rope is rolled. 

BARREL, (of a pump.) The cylinder, or hollow part of the pump, in 
which the piston works. 

BARROW. See W heel-barrow. 

BARYTES, found in tolerable abundance in Wales, and some parts of 
England, and also in the State of Connecticut. The salts of barytes 
employed in the arts and manufactures, are confined to the carbonate and 
sulphate. The use to which the native carbonate has been applied is the 
preparation of the various salts of barytes, which are made by saturating the respective i 
powdered native carbonate. 

An artificial carbonate is used in Birmingham in the manufacture of plate and flint glass, as a cheap 
substitute for part of the alkali. It is also used in the manufacture of porcelain, jasper, <fec. 

Sulphate of Barytes is employed as a pigment and also for the purpose of adulteration. It is known 
as u permanent white," and is made by precipitating the sulphate from a soluble salt of barytes, by 
means of sulphuric acid, which when washed and dried forms a beautiful white powder, that is not 
acted upon by sulphuretted hydrogen gas. It is to this that it owes its superiority over white lead as 
a water-colour. Oils destroy its whiteness, and render it nearly transparent ; so that it is only useful 
as a water-colour. 

The sulphate of barytes used in adulterating white lead is made by levigating the whitest varieties 
of the native sulphate, and afterwards bleaching it by boiling with dilute sulphuric or muriatic acid, 
for the purpose of dissolving out any iron which it may contain. "When washed and dried it forms a 
dense white powder. Some of the native sulphate is sufficiently pure as not to require the bleaching 
process. That which is white and soft, possessing little or no crystalline structure, is preferred by the 
manufacturer, being easily reduced to powder. The presence of barytes in white lead can easily be 
detected by dissolving out all the carbonate of lead, by dilute acetic acid. The sulphate of barytes 
being unacted upon, can then be washed, and the quantity ascertained by weighing. 

BASE LINES, (in surveying.) The main lines of a survey, upon which the correctness of the whole 
depends ; it is therefore necessary to proceed with the utmost care in the laying out of the several base 
lines of a survey. 

BASE LIKE. (In perspective.) The intersection of the plane of the picture with the ground plane. 

BASKET. A kind of vessel made of osier," wicker, rushes, straw, whalebone, &e. The weaving of 
baskets is entirely hand work, but simple machines are used in the splitting of the materials. For 
strong, heavy baskets, strips of ash are considered the most serviceable. 

BASE. A rest or support ; particularly applied to the bottom of columns, pedestals and edifices. 

BASES. In chemistry, a term applied to all the metals, alkalis, earths, and other bodies, which 
nnite with acids, or with gases. Thus in sulphate of copper, the copper is said to he the base of the 
ealt, from the supposition that the non-acid principle is that which gives diversity or distinctness of 
character to compounds. The term is now retained from its convenience, rather than the truth of tht 
above opinion. 

BAT. The name given to a half or other portion of a brick. 

cids with tha 


BATTENS. Strips of board or plank, from li to 6 inches wide, nailed over the joints of other hoards : 
often ornamented with a bead or corniced to give architectural effect on the cheaper class of houses. 
Batten doors are such as are made of two thicknesses of boards nailed together ; generally the boards are 
nailed crossways of each other, but often diagonally. 

BATTER. The face of a retaining, or other wall, when built in a leaning position, the top part fall- 
inn- back within the line of base ; walls of this description are sometimes termed tallus walls. The 
usual batter is from 1 to 3 inches horizontal for each vertical height. See Masonry. 

BATTERY. Two or more pieces of artillery, united for the purpose of dispersing troops, or destroy- 
fn°- that which covers and protects them. It is also used to signify the equipment of a certain number 
of pieces of ordnance. 

BAY. i n architecture, the space between the beams or arches. A part of a window between the mul- 
lions is often called a bay or day. 

BAY-TREE. See Woods, varieties of 

BEAM, in building, usually a horizontal piece of timber or metal. For the proper form of simple 
beams to resist the required strains, see Strength of Materials— for the relation of the parts of a 
trussed beam, see Bridge. The term working or walking beam is applied to the balance lever, trans- 
ferrin"- the power from the piston of common draught engines to the crank. See Engine. 

BEARING. That part of a 6haft or spindle which is in contact with the supports. See Geering. 

BEARING. The distance that a beam or rafter is suspended in the clear between supports. 

BED. A term used in masonry to describe the direction in which the natural strata in stoues lie ; it is 
also applied to the top and bottom surface of stones when worked for building. 

BED-MOULDINGS. A collective term for all the mouldings beneath the corona or principal pro- 
jecting member of a cornice. 

BEECH. See Woods, varieties of 

BEEF-WOOD. See Woods, varieties of. 

BEETLE. A heavy wooden mallet or rammer. 

BEETLLNG MACHINE. A machine used in bleacheries to give to cotton fabrics a soft, glossy ap- 
pearance. The usual form consists of a cylinder, on which, as the cloth is rolled, it is beaten by stamp- 
ers similar in their construction to those used in gold crashing ; see Metallurgy. An invention has 
been made to give the same finish by rolls as in a calender, of which the following is the description. The 
accompanying engravings represent at Fig. 230 a front elevation, and at Fig. 231 an end elevation of the 
above-mentioned machine, with the same letters of reference applying to similar parts. A A are cast-iron 
standard frames, having side-claw projecting bearings B B, Fig. 231, with two central horn-shaped ones 
A 1 , carrying the pressure-lever links ; C C are bush-bearings for the journals of the beetling rollers D and 
E, which rotate horizontally with each other in opposite directions ; F F is the roller upon which the cot- 
ton fabrics, about to undergo the beetling process, are wound ; G G is the pressure-roller, mounted in 
the lever-link motion-head H H, upon the central horn-standard/, in a manner subsequently explained ; 
I is the shaft upon which the pressure-roller revolves ; K K two connecting-rods on each side of the 
machine, attached in vertical positions at the top to the links H H, and at their lower ends to the 
weighted levers L L ; M is the centre stud, upon which the levers L L radiate ; N N are two spherical- 
shaped balls or weights, for giving pressure to the roller G, through the medium of the levers L L, as- 
sisted by their own gravity ; is the bearing on which the connecting-rods K K move ; P is an inter- 
mediate crank motion-rod, coupling the two way link-shafts V R, and giving motion horizontally to the 
longitudinal rest-bars T T, through the quarter-way links S S, in gear with the same ; U U are two 
spur-wheels, mounted upon the beetling roller-shafts D and E, in gear with a pinion V, on the driving- 
shaft ; W X is a long hand-lever, the object of which is to raise the different rollers from then- beds by 
it in the manner hereafter explained. Having thus far described the various arrangements and parts 
of which this invention consists, it is necessary to explain its mode of working, and the numerous advan- 
tages that may result from its application to the various purposes for which it is intended. Steam, 
or other motive power, is in the usual manner first applied to the driving-shaft W, which is 
mounted in a bracket bearing against the standard-framing, as represented in the engraving ; whilst 
the other end is similarly mounted against a wall or other convenient place, and when driven by the 
action of steam, it causes the pinion V, on the end, which takes into the spur-wheels U U, to propel 
the same, and thereby give the required motion to the machine or apparatus during the process of 
beetling. It must be observed, that the cotton fabrics about to be mangled or beetled, are first wound 
upon the roller F ; to accomplish which, the roller has to be removed or taken out of its place, which 
is performed in the manner hereafter explained. Having completed the operation of winding the cotton 
on the rollers, it is then passed between the beetling-rollers D and E, which are furnished with periph- 
eries, such as are seen in the two smaller engravings annexed ; these are embossed, or checkered 
in different patterns corresponding to the rollers employed. The fabrics are then taken from the 
rollers and replaced by others, during the working of the machine, and the operations effected. 
The pressure to which the fabrics are exposed by the constant rotation of the rollers between which 
they pass, is produced and carried hito effect as follows : — The roller G G, with its moveable liuk- 
Learings on each side, centred on the horn-shaped standards, are caused, through the medium of the 
eide connecting-rods K K, to receive the entire weight of the levers L L, in addition to the weights 
HH on the ends, and consequently oiler a sustaining pressure to the fabrics during the process ot 
beetling. On the other hand, when it becomes necessaiy to supply the apparatus with plain cotton fab- 
rics, and remove those already beetled, the levers L L, which are represented as having holes at one 
end for the employment of any suitable or convenient tackle, are to be by such means raised, the action 
of winch will have the effect of raising also the head-links and pressure-roller, and thus, by removing 
the weight, enable the roller beneath to be lifted out of its seat, and placed in one of the end claw- 
bearings B B, as represented by the dotted lines. The mode of effecting this part of the operations will 


be readily comprehended by reference to the engraving, Fig. 231, where T T shows a bar of iron hori- 
zontally placed on each side, beneath the journals of the roller F, forming a rail or table upon which 
they are to be moved. When a downward motion of the lever handle is given by the operator, it causes 
the coupling-rod P, through the medium links P R, in connection with others on the same shaft, in gear 
with the rest-bar TT, to move upwards horizontally, similar to the action of a parallel rule, and raise 
the rollers F or B out of, or into their respective places, by enabling the rollers to be rolled along 
them, when disengaged from their bearings or seats, and carefully lowered into their places, in readi- 
ess for the next operation. From these observations it will be seen that, first, the levers L L are 
o bs raised in the manner which will cause the roller G G to be also raised, through the medium of 

the connecting-rods KK, when the pressure will bo removed from the lower rollers, and wnich will 
enable them to be raised to the required height, so as to transfer them from one seat or bearing to 
another, and thus allow the fabrics to be changed by removing those already having undergone the 
process, and supplying the other roller with plain ones. The patentee, although he describes and sets 
forth the employment of the side-levers, yet does not confine himself exclusively, a9 other and equally 
effectual means may be applied with the same advantages, such as steam pressure, liquids, or other 
wise ; and in many cases the weight of the rollers themselves might be found sufficient to give the re- 
quired pressure without the intervention of additional pressure. 

The next object to which the patentee directs attention, is to the improved mode of construct- 
ing roller-mangles, which consists of very nearly the same arrangement of rollers, the only apparent 
difference being, the introduction of a flexible lever or spring, firmly fixed to the standards upon which 



the pressure-roller is mounted, being brought to act upon 
the same to any degree of force, by the application of a 
hand-wheel and screw-spindle, supported in bearings, suit- 
ably arranged. To the end of the screw-spindle two fixed 
studs are attached, between which the lower end of the 
flexible lever or spring is introduced, so that when the 
spindle is screwed to or from the centre of such stand- 
ard, carrying the roller, the pressure is applied by rea- 
son of the standard moving from a centre with the rol- 
er under an elastic pressure thus given by the forward 
or backward application of the screw hand-wheel spindle. 
The patentee states that cast-iron rollers may be employed 
for dry articles, but for damp ones, bell-metal would be 
found better adapted. One of the advantages derived 
from this system of mangling is the small space the ma- 
cliine occupies, together with the accommodation which it 
offers by being placed within a piece of furniture having 
drawers for the purpose of disposing of the various articles 
when so mangled, aud thus forming a very useful piece of 
furniture, and which may, if necessary, be rendered high- 
ly ornamental in place of the present incommodious mi- 
dline now in use. The same principle also extends to 
a portable description of mangle, which the patentee 
states may be temporarily set up on a table or dresser, 
and made to answer all the purposes for which it is in- 
tended, motion being given to it by hand-levers in the 
usual manner, but employing, as a means of giving pres- 
suie, a lever, as in the first-mentioned instance; but with tlus difference, that the connecting-rod K, 
in the beetling apparatus, has in this instance a rack and pinion as a means of adjusting it, so as 
to obtain the requisite pressure. The patentee, after describing the peculiar forms given to the several 
rollers comprising a series of different patterns, and the best means of constructing them and forming 
the corrugations or indentations upon them, would wish it to be distinctly understood, that lie claims 
as new and of his invention : — First, the employment of rollers having indented, grooved, checkered, or 
undulated surfaces or peripheries, for producing by pressure corresponding, marks or impressions there- 
with upon cotton or other fabrics. Secondly, for the general arrangement of parts constituting the 
action and construction of the said improved machinery. Thirdly, for the employment of water or 
other fluids witliin the aforesaid rollers, to act independently of other pressure apparatus, such as the 
long levers in Figs. 230 and 231, of the annexed engravings; also for the application of steam to such 
purposes, causing, in the usual manner by its expansion within a cylinder, a pressure to be exerted upon 
the rollers, and at the same time that such application should be available for the purposes of taking 
off and removing the pressure when required, the same means employed for the one shall be found 
effectual in performing the other. Fourthly, and lastly, for the use of the numerous patterns as applied 
to cylinders employed in the process of beetling, or to other like machines or apparatus, either for 
mangling, or otherwise, as hereinbefore fully detailed. See Calenders. 

BELLS. The hell of the Montreal Cathedral is the largest in America. Its proportions are as fol- 
lows: — diameter at mouth, 8 ft. 7 in., at shoulder, 4 ft. 8 in. Height to shoulder, 5 ft. 11 iu. Th« 
thickest part, or sound how, is 8 inches. Weight ISi tons. See Castings and Foundings. 

BELL-CRANK. A bent lever or arc, used chiefly in the hanging of hells, to allow the wire to ac- 
commodate itself to the alteration of motion requisite in turning corners. 

BELL-METAL. See Metals and Alloys. 

BELT, in building, a string-course and blocking-course ; a course of stones projecting from a wall, 
either moulded, plain, fluted or enriched. 

BELTING. A belt is a hand or strap, passing from one pulley over another, serving to convey mo- 
tion between shafts. Belting is usually employed at speeds varying from 300 to 5,000 feet per minute. 
The size of the belt will depend on the power to be transmitted. A certain degree of tension, varying 
with the width of belt and size of pulley, and, to a considerable degree, with the tractive nature of the 
surface of the pulley, as well as the amount of resistance, is required to prevent slipping. This force 
or tightness may be equal throughout its parts, while the machinery is at rest, but when in active op- 
eration, it becomes far otherwise. It is evident that the only force tending to induce motion in the 
driven pulley is the difference in tension between the two parts of the belt. A portion of the belt ex- 
tends from opposite sides of the pulley, in nearly parallel directions, and each portion tends by its pull 
to turn the pulley in opposite directions. If the driven shaft is performing any work, there must ne- 
cessarily be a difference iu the tension of the parts, and this, however rapidly the "belt may he moving, so 
that every portion is alternately exposed to a greater and a lesser strain. It is also equally plain, that oth- 
er things being equal, this difference in strain is directly proportioned to the amount of work or power which 
is transmitted. This then determined by dividing the power to he transmitted by the velocity ; 
thus, if a belt moving at a velocity of 1500 feet per minute, he required to transmit 5 horse power ; 

that is, 33000x5 = 165000 lbs. ft: then 16 ° 000 = 110 lbs., the strain on the belt to convey the 

power. In addition to this strain, it must be remarked, that the belt is stretched on the pulleys, so 
that it does not slip wdiile conveying the power. The strain given above may he considered approxi- 


mately as the difference of tension between tLe two sides. Morin gives the following Tafc_6 to deter 
mine the strain on each side of the belt. 


embraced by the 

New belts on 
. wooden drums. 

Ordinary belts 

Wet belts on iron 

On wooden drums. 

On iron pulleys. 


















4. S3 




























Application of the table. — Find in the table the value of K according to the given circumstances; from 
this number subtract unit or one, and divide the strain on the belt to convey the power by this remain- 
der, and the quotient will be the minimum tension or that on the slack side. Add to this quotient 10 
per cent, for friction due to shafting, or other causes. The tension on the leading or tight belt will be 
the above product added to the strain, as given by the power required to be conveyed. 

Applying this to the example above of a strain on the belt of 110 lbs. with the ordinary belt em- 
bracing ± or 0.50 of the circumference, the value of K in the table is 2.41 ; subtract 1, = 1.41 ; 110 
divided by 141 = 78 lbs. ; 

78 + 10 per cent, or 78 + 7.8 = 85.8, the tension on the slack belt. 

85.8 + 110 = 195.8, the tension on the tight belt. 

Good belting of an ordinary thickness of T 3 ff of an inch should sustain a strain of 50 lbs. per inch of 
width without risk, and without serious wear for a considerable time. Therefore, in the example above, 
the belt moving at a velocity of 1500 feet per minute, required to transmit a power of five horses 

195 8 
should be _-!. or very nearly 4 inches in width. 
50 , 
When the belt is shifted, whilst in motion, to a new position on a drum or pulley, or from fast to loose 
pulley, or vice versa, the lateral pressure must be applied on the advancing side of the belt, on the side 
on which the belt is approaching the pulley, and not on the side on which it is running off. It is only 
necessary that a belt, to maintain its position, should have its advancing side in the plane of rotation 
of that section of the pulley on which it is required to remain, without regard to the retiring side. On 
this principle, motion may be conveyed by belts to shafts oblique to each other. Let A and B (fig. 
be two shafts at right angles to each other, A vertical, 
B horizontal, so that the fine run perpendicular to the 
direction of one axis is also perpendicular to the other, 
and let it be required to connect them by pulleys and a 
belt, that their direction of motion may be as shown by 
the arrows, their velocities will be as 3 of A to 2 of B. 
On A describe the circumference of the pulley pro- 
posed on that shaft ; to this circumference draw a tan- 
gent a b parallel to m n, this line will be the projection 
of the edge of the belt as it leaves A, and the centre- of 
the belt as it approaches B ; consequently, lay off the pulley b on each side of this line, and of a diam- 
eter proportional to the velocity required. To fix the position of the pulley on A, let fig. 262 be an 



( 9' 


"I . 



other view taken at right angles to fig. 201, and let the axis B have the direction of motion indicated 
by the arrow, tb'.n the circle of the pulley being described, and a tangent a' b' drawn to it perpendicu- 
lar to the axis B as before determined, the position of the pulley on the shaft A is established. 

The position of the two pulleys are thus fixed in such a way, that the belt is always delivered by the 
pulley it is receding from, into the plane of rotation of the pulley towards which it is app-oachino-. If 


the motion be reversed, the belt will run off; thus (fig. 263), if the motion of the shaft A is reversed, 
the pulley B must be placed iu the position shown by the dotted lines. 

It is not an essential condition that the shafts should be at right angles to each other to have mo- 
tion transferred by a belt. They may be placed at any angle to each other, provided the shafts lie in 
parallel planes, so that the perpendicular drawn to one axis is perpendicular to the other. If otherwise, 
recourse must be had to guide-pulleys, which should be considerably convex on their face. 

It is to be observed that the faces of pulleys are generally made more or less convex, as the tendency 
of a belt in motion is to mount the highest part of the pulley ; by a slight rounding of the face, there- 
fore, the belt preserves its proper position. 

BENCH, or BERM. A ledge on the face of a cutting. 

BENCH MARKS, (in surveying.) Fixed points left on the line of survey, for reference at any future 
time, consisting of cuts in trees, pegs driven in the ground, and the like. 

BENDING OF TIMBER. See Woods, varieties of. 

BENZOLE. An oil prepared from coal tar, extremely volatile : if a stream of air be passed through 
a reservoir of Benzole, it will imbibe enough of the vapor to become an inflammable and luminous gas. 
On this principle many arrangements have been patented for illumination of buildings by benzole, but 
as vet the manufacture of benzole is too expensive. 

BETON. See Mortar. 

BEVEL, any angle except one of 90 degrees. The term bevel is also applied to an instrument for 
drawing angles, in general use among workmen. In construction, it somewhat resembles the common 
square, with this difference, that 

the blade is movable about a cen 
tre in the stock, so that it can be 
set at various angles. 


BINNACLE, a box near the 
helm, containing the compass. 

scription. — Fig. 234 is a side eleva- 
tion in section, and Fig. 235, a plan 
of the apparatus, (on a scale a lit- 
tle less than half size.) 

A A is the frame, supposed to 
contain the works of a portable 
timepiece, of which B is the fusee ; 
C is a hollow screw, fixed upon the 
frame A, through winch the axle 
of the fusee is prolonged, being 
supported by, and turning in a cir- 
cular opening at a, above which the 
axle is square, the diagonal of the ®8f 
square being equal to the diameter 
at a ; D is a hollow tube, having 
a female screw fitted into the bot- 
tom, to turn easdy upon the male- 
screw C ; the top of the tube D 
has a square opening to fit easily 
upon the square end of the axle of r^-f^ 
the fusee ; which axle should pro- 
ject about half an inch beyond the 
tube D, when in the position shown 
in the figure, to receive the key or 
handle used in winding up the 
timepiece ; E is the barrel or cyl- 
inder, round which the registering 
paper is placed, which should be 
made to fit upon the tube D, suffi- 
ciently tight to retain its position 
wherever placed, but capable of 
being easily turned round upon the 
tube, or slightly elevated or de- 
pressed, for the purpose of adjust- 
ing it to the index V, to show the 
time of the day, and also to adjust 
the registering lines with the prick- 
er G. F, the index showing the 
time, is a fine wire, placed verti- 
cally as near as possible to the cyl- 
inder, the ends being secured in a 
frame attached to A. The top of 
the frame also carries the pricker 
G, placed exactly over the wire F, 
which is acted upon, and makes an 



impression upon the registering paper, ■when a finger is pressed upon the stud H ; I shows a slight spring, 
intended to return the pricker and stud to their position when the finger is removed ; L is a piece of 
glass in front of the timepiece, the horizontal section of which is that of a double convex lens, but the sides 
vertically are parallel with each other ; this magnifies the parallel and diagonal hues upon the paper 
which show the minutes, horizontally only, showing the time more distinctly to the fraction of a minute ; 
K K are two pieces of plane glass, on each side of L, for the purpose of throwing more light upon the barrel. 

Fig. 236 shows a portion of the registering paper, of the full size, with the shaded lines upon it in 
dicating the days of the week ; tins paper is of exactly the circumference of the cylinder, and is put 
upon a strip of leather, gutta percha, or other flexible material, also of the length and width of the 
barrel, to each end of which is riveted a strip of brass, having a projection on each side to catch into a 
notch in the projecting flanges of the barrel! 'When the registering paper is changed, the barrel may 
be taken off from the tube D, and the leather and paper from the cylinder ; and then a new paper put 
on, the ends of the paper being turned underneath the leather, and retained by any adhesive applica- 
tion, such as that made use of in postage stamps. 

The registering paper is divided vertically by twelve equidistant parallel lines, representing the hours, 
and again subdivided between each of the above lines by other finer lines into ten minutes. On the lower 
edge of the paper are five parallel lines crossed by two diagonal lines between each of the above sub- 
division or ten-minute lines, by which each subdivision is again divided into minutes, the time of the 
day being shown by the point when the index wire F intersects these small parallel and diagonal 
lines. The shaded lines representing the days of the week are not drawn parallel with the edge of the 
paper, but in such a manner that when the paper is fixed round the barrel the shaded lines at one end 
of the paper fit opposite the intervals at the other end, these shaded hues and intervals being each ex- 
actly equal in width to the pitch of the screw C. 

Now, suppose the timepiece newly wound up, and a new registering paper placed upon the barrel at 
midnight on Sunday : (of course this untimely hour is not necessary, as the operation may be done at 
any time of the day.) The barrel will then have been removed from the position shown by the dotted 
lines in Fig. 234, to the shaded part above in the same figure, and the pricker G would then be oppo- 

site the commencement of the underside of the line II, (Fig. 236.) and every part of the underside oi 
that line would by 12 at noon have passed under the point of the pricker; when the barrel having 
made one revolution would also have descended one thread of the screw, and during the next revolu- 
tion the upper side of the fine JI, representing the afternoon hours of Monday, would have passed un- 
der the pricker, and so on through the week ; the lower side of the line representing each day passing 
under the pricker during the forenoon, and the upper side on the afternoon of such day. It is therefore 
obvious, that any impression made upon the paper bv the pricker, would show the day and the exact 
time of day when such impression was made, and when the paper was removed from the barrel the 
punctures remaining upon it would be an enduring testimony, to be consulted and checked at leisure, of 
the operations recorded upon it during the week. 

The uses to winch this tell-tale might be applied are various. If as a watchman's clock, it may be 
nsed by several people who are required to be at a certain spot at certain or uncertain intervals. When: 
a person presses upon the stud, he should be required to make a memorandum of the time by the clock 


these memoranda he would give up to the inspector at the end of the week, who would compare whether 
the punctures upon the paper corresponded with the return ; and if not, the writer would of course be 
detected making a false statement. In an establishment where there are a number of individuals, 
and it is desirable to ascertain the tune of their attendance, they might be required to write their names, 
and the time of their arriving, in a book, at the same time pressing the tell-tale ; when, although sev. 
eral might arrive and sign so near together that the punctures upon the paper might run one into an 
other, yet the time between the first and last would be distinct, and if the names were written in suc- 
cession, it would be evident that they had been written during the time between the first and last 
puncture. Again : any individual leaving an establishment during the day, might be required to write 
his name in the same way, with the time of his leaving and returning, at each time pressing upon the 
tell-tale, wliich would be a great check against a person absenting himself improperly, or being absent 
too long. It might also readily be applied to registering the performance of a steam-engine, or other 
machinery, by so connecting it with the machinery that the pricker should puncture the paper after a 
certain number of strokes of the engine, or otherwise. 

The tell-tale, as in the engravings, is shown attached to a portable timepiece, regulated by a balance 
escapement ; but it is applicable also to a common eight-day clock, with slight modifications. 

BIRCH. See Woods, varieties of 

BISMUTH, is a rare metal, hut its distinguished qualities are that it is very fusible, and causes other 
metals to become so. It melts when pure at 480° ; it may he distilled in a close vessel, and then crys- 
tallizes in laminae. It is very brittle, like antimony, and of a brilliant lustre ; its color is white, tend- 
inn- to flesh-color. Its specific gravity is 9-83, which may be increased to 9'S8 by hammering. It ex- 
pands in the act of cooling, which renders it peculiarly suitable for castings. 

The operation of smeltiug bismuth is extremely simple ; the metal having but a weak affinity for 
other substances is obtained by simply heating its ore in a modern liquation furnace, Fig. 23G. A, is a 

cast-iron retort, at. the highest part of which the crude ore is charged. B shows a cast-iron bowl into 
which the metal flows. About half a cwt. of broken ore is charged in each retort, of which there are 
four in a furnace side by side. This quantity nearly half fills a retort, so that the upper part of it is 
empty. The lower end of it is closed with a clay plate, or slab, provided with an aperture for the dis- 
charge of the melted metal. The pipes, when properly heated, soon cause the metal to flow into the 
dish B, which contains some charcoal- dust. By applying a brisk fire aud some stirring to the ore, all 
the metal contained in it is obtained within half an hour. The residuum of the ore is now scraped out 
of the retort into a trough with water, aud the pipes are filled afresh. About a ton of ore is smelted 
iu a day of eight hours. The metal is remelted, cast iuto iron moulds in the form of ingots, and is 
now ready for the market. See Metals and Alloys. 

BITS AND BRACES. See Boring Tools. 

BITTERNUT-WOOD. See Woods, varieties of. 

BLACK BOTANY-BAY WOOD. See Woods, varieties of. 


BLASTING. The operation of detaching aud separating blocks of stone or earth from their natural 
or quarry beds, which was usually performed in former times by the following process : — Long wooden 
wedges were driven, in a very dry state, into holes prepared for them, and previously well heated ; a 
quantity of cold water was tncu poured over the wedges, which, upon becoming thoroughly saturated, 
swelled and caused a fracture or the rocks. The same effects are now generally produced by the ex. 


ploding force of gunpowder, which was first used for that purpose about the year 1620. A hole is first 
driveninto the stone by a jumper, or chisel, which is held in a proper direction by one man while an- 
other strikes it with a hammer, the former turning his instrument at every blow, to form a round 
hole ; sunk to various depths, from 1 to 3 feet, according to circumstances. If water ap- 
pears in the hole, some stiff clay is crammed in, by which it is absorbed, and the fissures through which 
it entered filled up. When the hole is of some considerable size, and of great depth, a long runner suc- 
ceeds the jumper, 6 or 8 feet long, and chisel-pointed at both ends, which is lifted up and dropped 
into the hole, and being heavy, perforates the rock. For deep holes a second longer runner succeeds 
the first. When sufficiently deep, the hole is charged with powder, and a small taper rod or needle 
of copper is inserted, so as to reach the bottom of the hole ; the remaining space is tamped or filled up 
with broken bricks and clay ; the needle is now withdrawn, and the vent thus formed filled with fine 
powder, which is ignited by a match. 

Since the introduction of the safety-fuse, the copper needle is dispensed with, as well as the tamping bar, 
by the use of which premature explosions were frequent. The safety-fuse is made by machinery. 
String is coiled so as to form a cylinder, which receives the powder specially manufactured for the pur- 
pose, and by a continuous operation the fuse is formed in coils of any length. In practice, the charge 
of powder is placed in the hole and the required length of fuse carried down to it ; the hole is then 
filled slowly with dry sand and tamped with a pointed stick. The fuse is left projecting sufficiently 
above the hole to be readily lighted, and of length enough to enable the workmen to withdraw before 
the explosion. 

In blasting operations of magnitude, the steam drill is effectively employed. See Dkill. 

When it is desired to move large masses of rock, as in excavating ledges, it is usual to open a seam, 
as it is termed ; this is effected by drilling a very deep hole, and charging it with a quantity of powder 
only sufficient to separate the mass to be moved. The scam thus made is then partly filled by pouring 
in powder, and tamping it with dry sand. The charge is then ignited by means of a safety-fuse in the 
usual manner. 

The galvanic battery has been successfully applied to Blasting, both on land and under water. It in 
well known that a piece of platinum or iron wire when made to connect two copper wires leading from 
two poles of the battery, instantly becomes red-hot, and capable of igniting gunpowder, or even of ig- 
niting a spirit lamp. For dry blasting two insulated wires connected at the bottom with a piece of pla- 
tinum wire are inserted into the charge, and after the usual tamping, the powder is exploded by estab- 
lishing a galvanic current through the wire by means of a battery. For submarine blasting, mora 
precautions are necessary to insure the insulation of the wires and the keeping of the powder dry. The 
charge of powder is contained in a canister, in the top of which is fixed a cork coated with 
sealing-wax, through which descend, water-tight, two vertical copper wires, reaching into the middle of 
the charge. These are separate during their whole course except at the bottom, where they are con- 
nected by a fine platinum wire ; and at the top they rise a little way above the cork, and are curled 
round into two distinct loops. After the charge is introduced, the top is cemented on the canister with 
putty ; two copper wires, wound with cotton and coated with varnish, are then connected with the 
wires in the canister, one to each loop, and of sufficient length to reach from the point of explosion to 
the battery, which is at a sufficient distance to insure safety, either in a boat or upon land. A double 
chain of communication then exists, properly insulated, from the boat to the charge of powder, which 
has been fixed in the required position by a diving bell or other means. It is then only necessary to 
bring one wire into connection with each pole of the galvanic battery, which by the passage of the gal- 
vanic fluid heats the platinum, and ignites the powder in the canister. A battery of six cells is suffi- 
ciently powerful when usiug a length of 100 yards of wire. 

The galvanic battery was employed in the operations at Hound-Down Cliff, near Dover, Eng., in 
1S43, when a mass of chalk estimated at 291, 6G6 cubic yards was displaced by a single explosion of 
1S,000 lbs. of gunpowder, ignited by the galvanic current. The wires used were each 1,000 feet in 
length, and it was ascertained by experiment that the electric fluid will fire powder at a distance of 
2,300 feet of wire. 

Blasting under water. The method of blasting rock under water, by the aid of the diving bell, as 
practised in Ireland, is as follows : — Three men are employed in the bell : one holds the jumper or 
boring iron, the other two strike alternately quick, smart strokes with hammers. When the hole is 
bored of the requisite depth, a tin cartridge filled with gunpowder, about two inches in diameter and a 
foot in length, is inserted and sand placed above it. To the top of the cartridge a tin pipe is soldered, 
having a brass screw at the upper end. The diving bell is then raised up slowly, and additional tin 
pipes with brass screws are attached, till the pipes are about 2 feet above the surface of the water. In the 
old practice the tube was filled with powder in a train, and fired ; but in many instances the heat 
melted the solder of the pipe, and the water entering extinguished the fire. The improved method is 
to leave the tube empty. The man who is to fire the charge is placed in a boat close to the tube, and 
to the top of the tube a piece of cord is attached, which he holds in his left hand. Having in the 
boat a small portable furnace with small bits of iron red hot in it, he takes one of the bits of iron with 
a pair of nippers and drops it down the tube, which instantly ignites the charge and blows up the rock. 
A small part of the tube is destroyed next the cartridge, but the greater part, which is held by the 
i/ord, is reserved for future service. The workmen in the boat experience no shock by the explosion ; 
but those who stand upon the shore or upon any part of the rocks, connected with those blasted, feel a 
very strong concussion. A certain depth of water above the charge — at least 12 feet — is necessary for 
safety. The workmen are generally down in the diving bell 5 hours in the day without coming up ; 
and in the summer one set of men are down 10 hours one day, and 5 the next, and so on alternately. 
Figs. 237, 238, are sections and plans of means adopted by blasting to improve the navigation of 
the river Severn. Pipes 3i to 4 inches in diameter, T 3 j- an inch thick, and 9 feet long, were driven at 



intervals of 6 feet from each other, through the gravel into the marl, 
boring of the holes into the marl. 

These formed curbs for tie 

/ / VWi 

Tlie holes were bored two feet below the proposed bottom of the dredging, as it was expected that 
each shot would dislocate, or break into small pieces, a mass of marl of a conical or parabolic form, of 
which the bore-hole would he the centre, and its bottom the apex, so that four adjoining shots -would 
leave between them a pyramidical piece of marl, where the powder would have produced little or no 
effect. By carrying the shot-holes lower than the bottom of the intended dredging, the apex only of 
this pyramid was left to be removed, and in practice this was found to foi-m but a small impediment. 
Figs. 237, 238. 

The cartridges, or charges, were formed of strong duck or canvas bags, somewhat tapered at the bot- 
tom ; these were filled with the required charge of powder, varying from 2 lb. to i lb., according to 
the depth of the marl ; the weights of powder used for depths of i feet, 4 feet six inches, and 5 feet, 
were respectively about 2 lb., 3 lb., and i lb. The end of a coil of Bickford's patent fuse was inserted 
to the^ centre of the powder, and the neck of the bag was carefully gathered up round the fuse, and 
well tied with small twine, ff the cartridge was small, it was then dipped into melted pitch, which 
had about one-fourth of tallow melted with it, or otherwise the melted pitch was ladled over it, till it 
was uniformly coated ; in this state, the cartridges were hung to drain and stiffen. When hard, they 
were well rubbed over with tallow, and lastly powdered over with dry whiting. The tallow, whilst it 
ensured the stopping of any little cracks in the pitch, facilitated the passage of the cartridge down the 
hole ; the whiting also prevented the pitch from adhering to any thing. 

The charge was carefully pushed down into the hole by a wooden ramrod of suitable diameter, with 
the end rounded ; the same instrument was used for ramming down the tamping. The material found 
to answer best for this purpose, was the small fragments of hard marl, separated by the action of the 
weather from the lofty escarpment at each of these shoals ; this was gradually filled into the holes, 
and rammed solidly, till the bore was full up to the surface ; the timber-dogs which held the pipes were 
then removed, the pipes were loosened from the marl, ropes were attached to the pipes and to the raft, 
or to some loose pieces of timber, and the shots were fired. 

Mr. Maillefert bases his method of blasting beneath water without drilling, on the great resistance 
which the water offers to the passage of bodies through it, and which is as the squares of the velocity 
and the mass of water to be displaced ; hence by placing a charge of gunpowder on or against the sur- 
face of .the rock to be blasted, at a proper depth uuder water, and by firing off that charge, the consid- 
erable volume of gas which is almost instantaneously produced by such an explosion, would, in forc- 
ing its way through the water, meet with a resistance which would make it act in all directions, though 
in a different degree, somewhat like powder confined in a mine, and that the proportion of the concus- 
sion which would thus be directed against the rock, would be sufficient to disintegrate even the hardest 
and most tenacious kinds. 

This conclusion proved perfectly correct in all cases where a proper proportion existed between the 
•epth of water above the charge, the quantity and quality of the powder exploded, and the characte' 
ef the rock. 



The mode of procedure in carrying out this method of blasting is as follows : 

Having inserted an insulated conductor into a canister, made of tin or other suitable material, it is 
filled with gunpowder, and closed up so as to prevent access of the water. The cylinder is then lower- 
ed on the rock, from a boat or float, and by means of a rope or chain. Sliding along the guide-rod, it 
is placed exactly on the spot to be blasted, after which the guide-rod is withdrawn, the boat or float 
moved away far enough not to be injured by the agitation of the water consequent upon the explosion, 
which is effected by connecting the conductor with a galvanic battery, also placed at a suitable 

The results obtained in Hell-Gate, where nearly sixteen hundred cubic yards of the hardest rock 
(Gneiss) have been broken down and removed under very difficult circumstances, as an experiment, 
in less than seven and a half months, are sufficient to indicate what is to be expected from this method 
of blasting. 

BLAST. The air introduced into a furnace. 

BLAST MACHINES. In most metallurgical operations, the fire is urged to the proper degree of 
heat by forcing air into the fuel. This is done by machines which are driven by power. The pressure 
of the blast thus generated, and the velocity with which it enters the fuel, is greater .or less according 
to' the kind of fuel, and the effect which it is intended to produce. The most common blast machines 
are smith's bellows : these, however, are of limited use in smelting metals. Cylinder machines are 
constructed with a double and single stroke ; wooden ones are generally of the latter, and the iron 
of the first description. In addition, there are machines with one, two, and three cylinders. One of 
the chief aims in constructing a blast machine must be to produce a uniform pressure. This is difficult, 
even with a regulator attached. Most of our blast machines do not furnish that uniformity which is 
required. Fig. 254 is a vertical section of a wooden blast machine ; A, A, are two simple working cyl- 
inders, in each of the pistons of which there are two valves. On the top of these cylinders there are 
valves which lead to the regulator B, in which a piston moves that is connected by an iron piston-rod 
with the weight C. A balance beam D, sets both pistons A A in motion, and is itself moved by a crank 
pin and connecting-rod from the wheel E, which, again, is moved by a water-wheel or a steam-engine 

The whole machine is fastened to substantial timbers, which rest upon a good foundation of hewn stones. 
These cylinders and the regulator, are from Si to 5 feet in diameter, and not often of more than 3 feet 
stroke. The cylinders are constructed of segments of circles cut out of li inch plank of dry ash wood, 
and well nailed and glued together. The fibre of the wood runs then parallel with the circumference. 
This form secures great solidity, prevents warping, and affords so much strength, when the thickness of 
the sides is at least three inches, that no iron hoops, or hinders of any kind, are required. When the 
interior surfaces of the cylinders are well covered by a coating of fine plumbago, there is not 
much friction. Fat, grease, or oil of any kind, should not he put within a blast cylinder. Black- 
lead and glne, formed to a thin paste, is the best lubrication in this case. From 15 to 16 strokes 
per minute may be made with this machine. The packing of the pistons may be either of metal, wood 
Dr leather, although the latter is generally chosen. The valves are constructed of dry, light wood, and 
a close fit is secured by a piece of leather or of vulcanized rubber, which at the same time serves 
the purpose of hinges. In wooden cylinders the pressure cannot well be increased above f of a pound 
to the square inch. 

To obviate the use of a regulator, machines have been constructed with three blowing cylinders, the 
strokes being made to lap on to each other, as in fig. 255. Two hollow cast-iron beams, A, A, support 
the cylinders, and one serves in the mean time as the conductor of the blast, in the other the snckin" 


valves are located. At the top is a round pipe, B, running the length of the machine in which the blast 
is gathered from the upper parts of the cylinders. The upper and the lower pipes are connected by an 
upright pipe, and from this the blast is conducted to the desired spot at the furnaces. 


Another species of blowing-machine is the water-bellows. The nature of these machines will be 
readily understood by the help of the following diagram. The side figure is a vertical section of th« 
machine, a is the fulcrum of the lever or beam, with 
two inverted vessels, 6 and c, suspended from its ex- 
tremities ; these vessels are open underneath, but 
air-tight above, d and e are two larger vessels, 
tilled with water to the same level, in which the 
vessels 6 and c rise and fall alternately, g h i is 
a tube or pipe, which passes through the vessels d 
and e, and reaches above the surface of the water ; 
at the extremities are two valves, wdiich respect- 
ively open outwards into the inverted vessels, with a 
pipe at h open to the atmosphere, h and I are pipes 
passing through the bottom of d and e, and extending 
a little above the surface of the water; they are 
open at top, and have valves at bottom opening into 
the trunk o, to which the pipe is fitted which con- 
ducts the blast to the furnace. An alternating mo- 
tion being imparted to the beam by a steam-engine or other first mover, the air passes up the tubes g h i, 
and fills each inverted vessel as they are successively drawn up out of the water ; the descent of the 
inverted vessel closes the valves at g and i, and opens those at the bottom of the tubes k and I, through 
which the air is driven forward by the trunk o, and thus by the reciprocation of the beam, a continual 
blast is maintained through the trunk o and the tuyere of the furnace. 

A blast machine should he carefully constructed, in order to obtain the best results from it : iron ones 
are in all cases preferable. The piston is generally made similar to that of a steam engine. The form 
and position of the valves is one of the most important points connected with a blast machine. Air 
being elastic, expands when the pressure upon it is released : the compressed air ought to be driven out 
altogether at each stroke. We may locate the valves horizontally in the cylinder heads, even when the 
cylinders are vertical, as has been shown in fig. 254, but the weight of the valve is an objection to this. 
The vertical valve has a decided advantage. In whatever form the valve may be applied, waste room 
ought to be aveided. Valves should be as light as possible : the wooden valve lined with leather or 
vulcanized rubber, is for these reasons preferable to one of metal. In order to diminish the bad effects 
arising from the weight of valves, their number may be increased ; this affords more space for the pas- 
sage of air without increase of weight. 

The size of a blowing cylinder depends upon the volume of air which is wanted. The stroke of the 
piston is generally limited by parts of the machinery depending on the locality and on the moving 
power ; the number of strokes is also subject to considerations of economy and locality. A speed of 
3 feet per second is considered an average velocity : multiply the velocity by the surface of the piston 
in feet, to obtain the quantity of air of the blast per second ; but as blast is lost by leakage and waste 
room, multiply that result by f for iron cylinders, and by $ for wooden ones. The quantity of air ne 
cessary in the consumption of a certain quantity of fuel, must be so calculated as to be sufficient to os 



Idize it to the highest degree. It requires 100 pounds of air to convert 8'1 pounds of carbon into car- 
bonic acid, in case all the oxygen is consumed. But this is not often accomplished; therefore 6 pounds 
may be assumed in reverberatories, "which, in many instances, such as in reheating and roasting fur- 
naces, is reduced to 5 and even 4 pounds of coal to 100 pounds of air. It has been ascertained at blast 
furnaces, that, when the quantity of fuel used during 12 hours in pounds is divided by 5, it shows the 
number of cubic feet of air required in one minute. Thus, "when a blast furnace is to consume twenty 
charges of charcoal, of 15 bushels each, during 12 hours, and the charcoal weighs 20 pounds per bushel, 
the quantity of air which must be furnished to the furnace in each minute, of atmospheric density, is 

15x20x20 ,„„„ ,. , . 

— . = 1200 cubic feet. 

Regulators. Piston blowers do not form a blast of uniform density ; but as this is, inmost cases, of 
the utmost importance, particularly in blast furnaces, regulators are attached to these machines. At pres- 
ent sheet iron right cylinders, of from 4 to 8 ft. in diameter, and from 15 ft. to 40 ft. in length, are gene- 
rally adopted as the most suitable and best forms. The thickness of the sheet iron is not often more than 
^ of an inch, frequently less ; the heads are formed of cast-iron, or of sheet-iron and stiffened by wood 
and iron screws. This chamber, or regulator, is provided with a safety-valve, to insure it against burst- 
ing from excessive pressure. The blast is introduced at one end, and tapped at the same or the opposite 
end. The equalization of the blast is produced by the elasticity of the air. It is easily understood, 
that in a large chamber the pulsations of the blast machine are not so strong as in a small one, but the 
size must be limited for reasons of economy. As a general rule, it is established that the capacity of 
this regulator should be from 10 to 18 times that of one of the blast cylinders ; but harm ensues if it is 
larger. For charcoal furnaces it should have a capacity at least 20 or 25 times that of the cylinder ; it 
may be smaller for anthracite and coke furnaces. 

BLOCKS, in the Navy aud Marine Architecture, a species of pulley very extensively used for moving 
heavy weights, by means of ropes or chains passing over the pulleys ; also occasionally in architeetura! 
and other works. A block consists of one or more pulleys, called sheaves, which are generally formed 
of lignnmvitie, or some hard wood inserted between cheek pieces, forming what is called the shell of 
the block, and turning upon a pin passing through the shell and the centres of the sheaves. Blocks are 
suspended by straps, either of rope or iron ; the latter are called iron-strapped blocks, and have fre- 
quently a swivel-hook. A combination of two blocks, one of which is attached to the load to be raised, 
is called a tackle, and the power is to be estimated by the space through which the fall (which is that 
part of the rope to which the power is applied) passes, compared with the space through which the load 
is raised, deducting for friction, which is great, owing to the rigidity of the ropes, and the small diame- 
ter of the sheaves ; these, for nautical purposes, are necessarily limited by considerations as to weight 
and space. 26S. 2J k 

The shells are almost inva- 
riably of wood, in the smaller 
blocks being made of a single 
piece of wood, with a channel 
morticed for the reception of 
the sheave. Formerly almost 
all blocks were made in this 
manner, and beautiful and ef- 
fective machines were made at 
the Woolwich Dock, by Sir. 
Bennet, for forming the differ- 
ent parts of a block, but in this 
country the shells are now 
made in pieces, and bolted or 
riveted together at the top and 
bottom. Each block is furnish- 
ed with a strap or band of rope 
or iron, encircling it and ter- 
minating in an eye or hook. 
A block having a fixed position 
is called a standing block, whilst 
one which is attached to the 
weight and hoisted with it, is 
called a running block. A 
Snatch block consists of a single 
sheave with anotch cut through 
one side of the shell to allow the rope to be lifted in or out without inserting it end first. Figs. *266, 267, 
is a form of block in common use for shipping in this countiy. Its construction is easily understood 
from the figure. The block is double, or with two sheaves, and the shell consists of three largo pieces 
with four pieces inserted between them at the top and bottom of the block. The whole is firmly 
bound with an iron strap. Figs. 268, 269, represent the construction of sheaves, with iron bushings 
the collars and rivets being counter sunk. Fig. 270 is an elevation of a sheave showing an arrangement 
of friction pulleys or roils, to admit of an easier motion. 

Figs. 271, 272, represent a front and side elevation of a single block complete, constructed according tn 
Waterman aud Russell's Patent.f Figs. 273, 274, represent a like view of a double block of tho same Pa- 
tent with the shells removed. 

Mas. Carroll, Burl'Dg Slip. 

t Burr & Co., South st. N. Y. 



The peculiarity of these hloeks consists in the iron straps being closely adjusted to each side of the 
sheave, so as barely to have its discs free of lateral friction, and then being made to combine in a solid 
iron bar, at just sufficient distance from the periphery of the sheave to leave the rope space to ruu with- 
out chafing, while the combined bar or straps extend sufficiently without the block to form the hooks at 
each extremity. These blocks are in many respects to be preferred to the old-fashioned blocks, whose 
,ron straps are a mere hoop around the wood of the block, leaving all the space of the wood between 

.nis hoop and the sheave for the pin to spring or bend. Thus a much larger pin is required, which of 
course will produce more friction, and besides, it cannot be hardened to inflexibility or be made of har- 
dened steel, lest it should break ; from the leverage which the weight on the sheave exerts on the support 
of the pins, the iron at the outside of the blocks. If the pin should bend, the friction it produces would! 
not only be increased by cutting the corners at the discs where it passes through the sheave, hut the 
sheave is exceedingly liable to be canted to the right or left, and to suffer in consequence a lateral fric- 
tion, from contact with the wood of the block. But the patent iron-strapped blocks admit of no such 
leverage. The straps being close by the sides of the sheave, preclude the bending of the pin in the least., 
and give only the advantage of dead weight to the power that could be exerted to break it. Indeed, 
this weight must be sufficient to cut the pin square off by dead force before it will give way, and this 
without the advantage of any bend or twist whatever. The pins of these blocks are of hardened steel. 
At their introduction, these blocks were tested at the Navy Yard, AYashington, and were found superior 
to their own blocks ; they are now much used in every service. 

There is a species of blocks termed " Dead-eyes," which are used for tightening or setting up, as it is 
called, the standing rigging of ships. It consists merely of a circular block of wood, with a groove on 
its circumference, round which the lower end of the shroud, or an iron strap, is fastened : three holes 
passing through the face, (ranged in a triangle.) to receive the laniard or smaller rope, which forms a 
species of tackle for tightening the shrouds. There are no sheaves in the dead-eye, but the edges of 
the holes are rouuded ofF to prevent cutting the lanyard ; but this very imperfectly answers the purpose ; 
as from the roughness of the grain of the wood, which is usually elm, and from the stillness of the 
rope, the laniard renders with difficulty ; and from the great strain to which it is subjected, it is fre- 
quently broken. A very simple and effectual improvement has been made in this respect, by inserting 
a half-sheave of lignumvita? into each of the holes which causes the laniard to render with greater fa- 
cility, and the shroud to be set up in half the usual time. 



BLOW-PIPE. An instrument for exciting intense combustion upon a small scale; it is extensively 
used in many branches of the arts, and also in philosophical experiments upon metallic substances. In 
its simplest form it is merely a conical brass tube, curved at the small end, in which is a very minute 
aperture ; and a stream of air being urged through it by the mouth against the flame of a lamp or 
candle, a heat equal to tliat of the most violent furnaces may be produced. The body intended to be 
operated upon should not exceed the size of a peppercorn, and should be supported upon a piece oi 
ivell-burned, close-grained charcoal, unless it be of such nature as to sink into the pores of the charcoal, 
or to have its properties affected by its inflammable quality. Such bodies may be placed in a small 
spoon made of pure gold, silver, or platinum. Many advantages may be derived from the use of this 
simple and valuable instrument, It is portable ; the most expensive materials, and the minutest speci- 
mens of bodies, may be used in the experiments ; and the whole process is under the eye of the 
observer. In the blow-pipes used by enamellers, glass-blowers, and others, the current of air is main- 
tained by a small pair of double bellows. 

Early in the present century, Dr. Hare, of Philadelplua, made a most important improvement in 
the blow-pipe, by substituting for the flame of a lamp that arising fi-om a mingled current of oxygen 
and hydrogen, of which we shall treat presently. 

The Hydrostatic Blow-pipe consists of a cask, divided by a horizontal diaphragm into two parts D D. 
From the upper apartment, a pipe of about 3 inches diameter (its axis coincident with that of the cask) 
descends, until within about inches of the bottom. On this is fastened by screws, a hollow 
eylinder of wood B B, externally 12 inches in diameter, and internally 8 inches. Around the 
rim of tliis cylinder a niece of leather is nailed, so as to be air-tight. On one side a small groove 



is made in the upper surface of the block, so that 
a lateral passage may be left when nailed on each 
side of the groove. This lateral passage com- 
municates with a hole bored vertically into the 
wood by a centre-bit ; and a small strip of leather 
being extended so as to cover this hole, is made, 
with the addition of some disks of metal, to con- 
stitute a valve opening upwards. In the bottom 
of the cask there is another valve opening up- 
wards. A piston-rod, passing perpendicularly 
through the pipe from the handle H, is fastened 
near its lower extremity to a hemispherical mass 
of lead L. The portion of the rod beyond this 
proceeds through the centre of the leather which 
covers the cavity of the wooden cylinder ; also 
tlirough another mass of lead like the first, which, 
being forced up by a screw and nut, subjects the 
leather between it and the upper leaden hemis- 
phere to a pressure sufficient to render the junc- 
ture air-tight. From the partition, an eduction- 
pipe E is carried under the table, where it is 
fastened by means of a screw to a cock which 
carries a blow-pipe, so attached by a small swivel- 
joint as to be adjusted in any required direction. 
A suction pipe passes from the opening covered by 
the lower valve, under the bottom of the cask, and 
rises vertically close to it on the outside, terminating 
in a union-joint for the attachment of any flexible 
tube which maybe necessary. The apparatus being 
thus arranged, and the cask supplied with water 

until the partition is covered to about the depth of 2 inches, if the piston be lifted, the leather will be 
bulged up, and will remove in some degree the atmospheric pressure from the cavity beneath it ; con- 
sequently the air must enter through the lower cavity to restore the equilibrium. When the piston is 
depressed, the leather being bulged in an opposite direction, the cavity beneath it is diminished, and 
the air being thus compressed, forces its way tlirough the lateral valve into the lower compartment ot 
the cask, which compartment being previously full of water, a portion of the fluid is pressed up through 
the pipe into the upper apartment. The same result ensues each time that the stroke is repeated, so 
that the lower compartment soon becomes filled with air, which is retained by the cock untd its dis 
charge by the blow-pipe is necessary. Dr. Hare, in his oxy-hydrogen blow-pipe, did not mix the gases 
in his gas reservoir, but supported the flame of the hydrogen by a current of oxygen issuing from 
different jets. Subsequently, it was found that the heat produced was materially affected by the 
■proportions in which the gases were mixed, and that the greatest intensity of heat was obtained by 
two volumes of hydrogen united with one of oxygen ; and various attempts were made to mix and 
burn the gases in their due proportion, but with little success, until the important improvement effected 
in the instrument by Dr. Clarke, Professor at Cambridge. This improvement consisted in first mixing 
the gases in a bladder, in the exact proportions to form water, and afterwards condensing them in a 
strong iron chest, by means of a condensing syringe. To an opening at the end of tliis chest he attached 
a great number of layers of fine wire gauze, tlirough which the mixed gases were driven by their 
elastic force into a small tube, at the end of which they were inflamed. By this arrangement he ob- 
tained a much greater heat than had been effected by Dr. Hare's invention, and was enabled to make 
a great number of experiments highly interesting to science. Unfortunately, however, for the general 
adoption of Ins plan, it was soon found that his instrument was unsafe to use ; that the wire gauze 
would not prevent the explosion of the gases ; that in several cases, when used by the most experienced 
and cautious operators, the instruments were burst. The explosions were tremendous, and resembled 
the bursting of a bomb, the fragments of the iron chest being scattered with great force in all direc- 
tions. After trying various plans to render the invention safe, the Doctor, as a protection, had the iron 
chest placed behind a brick wall at the back of the operator, the gases being conveyed through a tube 
passing through the walL In this state the instrument remained, until Mr. Goldsworthy Gurney applied 
himself to its improvement, and after numerous experiments, which are highly interesting, and are 
fully detailed in Ins published lectures, he succeeded in producing an instrument unattended with the 
slightest danger in its use, and admirably adapted both for scientific investigation, and for various 
operations hi the arts. The annexed engraving is a representation of the instrument. A is the safety- 
chamber ; B a water-trough, through which the gas is made to pass from the gasometer D by the cock 
C, through a tube which reaches to the bottom of the water-trough; E is a cock fitted into the neck of 
the same, from which it is thrown out should an explosion take place on the surface of the water. F 
is a gage, to indicate the necessary height of the column of water in the trough. G is a transferring 
bladder, which is made to screw and unscrew to and from the stop-cock H, for the purpose of supply 
ing the gasometer with gases, which may be charged and recharged at pleasure, by an assistant, 
during its action, so as to keep up the most intense flame for any length of time. A valve is placed 
between the gasometer and the transferring bladder, which prevents the return of the gas. 1 1 is a 
light wooden or stiff pasteboard cap, which combines sufficient strength with great lightness, so that in 
ease an explosion of the gasometer should happen, it is merely thrown a short height into the air, by 
the force breaking the strings which connect the cap to the press-board. To these strings are attached 



email wires which pass through the table of the instrument, as at L, into tne press-board below, where 
they are seemed ; tin's press-board is kept in a horizontal position by the stand, so that when the re- 
quisite pressure is given to it, the cap 1 1 is brought to bear equally on the gasometer D. The gas- 
ometer bladder (or silk bag) is tied to a piece of bladder, which screws into a long tube laid into and 
across the table, wduch permits it to be unscrewed at pleasure from the body of the instrument, and 
immersed in water when it requires softening, affording also the means of fixing on another bladder, if 
any accident should render it necessary. The stop-cock of the charging bladder G is fixed to one end 
of the tube just described, and the stop-cock of the water-trough on the other end. To operate with 
this instrument, pressure by the hand is applied to the press-board, which draws down the cap 1 1 on 
the gasometer D, and forces the gas which it contains tlurmgh the stop-cock C, and through the water- 
tube and safety-chamber A, to the jet at the end, where it is burned. When the pressure on the press- 
board is too slight, or when the hand is taken off, the flame returns into the safety -chamber, and is 
extinguished. When it is required to suspend the operation, the hand need only be taken off the 
pressing-board ; the water in the trough acts as a self-acting valve in preventing the escape of gas 
iiom the instrument, and saves the necessity of turning the stop-cock. A silk tube is attached to the 
end of the tube before described, in the water-trough, which prevents the splashing of the water, 
sometimes occasioned by unskilful management. We omitted to state that the safety-chamber A is 
filled with numerous disks of very fine wire gauze closely packed, and should the flame be driven 
in, which will sometimes happen, it will not enter the bag or reservoir D, but will explode above 
the surface of the water in the chamber B, merely driving out the cork. An improvement has, how- 
ever, been since introduced in the construction of the safety-chamber, by Mr. Wilkinson, by which the 
retrograde motion of the flame appears to be effectually prevented, and a much larger jet may be 
employed than heretofore with perfect safety. This improvement consists in filling the chamber A 
with alternate layers of who gauze and of asbestos, previously beaten with a mallet, and pulled out 
to resemble floss silk. Mi-. Wilkinson received from the Society of Arts a silver medal for his com- 
munication on the subject, and we understand that Mr. Hemming has recently made some further im- 
provements in the construction of the instrument. We must here advert to the wonderful effects 
produced by the oxy-hydrogen blow-pipe, which almost instantaneously reduces the hardest and most 
refractory substances. Gun-flints are instantly fused by it, and formed into a transparent glass ; china 
melts into a perfect crystal. All kinds of porcelain are readily fused, previously assuming a beautiful 
crystaUized appearance. Rock crystal is quickly melted, giving out a beautiful light. Emerald, sap- 
phire, topaz, and all the other precious stones, melt before it into transparent glassy substances. Barytes, 
strontian, lime, and alumina, exhibit very striking and beautifid phenomena. Magnesia fuses into hard 
granular particles, which will scratch glass. The metals, even platina, are all quickly fused by it ; and 
all descriptions of stones, slates, and minerals, are melted, sublimed, or volatilized, by its all-subduing 

BLOW-PIPE. Dr. Hake's Hydro-oxygen; On certain improvements in the Construction and Sup- 
ply of the Hydro-oxygen Blow-pipe, by which Rhodium, Iridium, or the Osmiuret of Iridium, also Plati- 
num in the large way, have been fused. By Robert Hare, M. D., Professor of Chemistry in the University 
of Pennsylvania. 

While a pupil of my predecessor, Dr. Woodhouse, in the year 1S01, having observed that a jet of 
hydrogen when inflamed in atmospheric air, of which only one-fifth is oxygen, was productire of a heat 
of pre-eminent intensity, I was led to infer that in combining with pure oxygen, the gas in question 
ought to produce a temperature at least five times as great. This led to the contrivance of two modes 
of producing a jet consisting of a mixture of hydrogen with oxygen. Agreeably to one mode, the 
gaseous currents, meeting like the branches of a river, were made analogously to form a common 
stream. This object was accomplished by means of perforations drilled in a conical frustrum of pure 
silver, so as to converge until met by another shorter perforation, commencing at the opposite surface, 
and so extended as to join them at the point of their meeting. The other mode was that of causing one 
tube to be witliin another, so as to be concentric, the outer tube being a little the longer of the two ; 
the latter being employed for hydrogen, the former for oxygen. 

In the year 1814, tins last-mentioned mode was improved, so as to have the means of seeming, by 
adjusting screws, the concentricity of the tubes, and varying the distance of the orifice of efflux of the 
inner tube from that of the other. 

The constructions employed in 1801, were described and pubbslied in a pamphlet, and afterwards 


republished in Tillock's Philosophical Magazine, vol. xiv., and in Annals de Chymie, vol. xiv. At the 
same time an account was given of the fusion of pure lime and magnesia, and of the fusion of platinum. 
Subsequently, in a paper published in the Transactions of the American Philosophical Society, it was 
mentioned that I had volatilized platinum. 

About the year 1811, Professor Silliman, in a memoir read before the Connecticut Academy of 
Sciences, gave an account of a series of experiments, in which the experiments which I had performed 
were repeated, and many additional fusions made. I had adverted to the intensity of the light pro- 

uced during the exposure of lime to the flame. Alluding to the heat and light, my words were, " the 
yes could not sustain the one, nor the most refractory substances resist the other." The intensity o 
he light was still more insisted upon by Silliman. 

My experiments were also repeated by Mr. Rubens Peale, during many successive years, at the 
Philadelphia Museum, for the amusement of visiters. 

About the year 1813-14, it was ascertained, at the laboratory of Dr. Parrish, that a bladder being 
supplied with a mixture of hydrogen and oxygen, in due proportion, and punctured by a pin, while 
subjected to compression, on igniting the resulting jet, the gas within the bladder did not explode. Of 
course, a burning jet of flame thus created was found competent to produce, while it lasted, the same 
effect as when otherwise generated by the same gaseous mixture. 

Soon after this result was obtained, Sir Humphrey Davy discovered, that if a lamp flame be com- 
pletely surrounded by a gauze of fine wire, it may be introduced into an inflammable gaseous mixture 
without causing it to explode. This was ascribed to the refrigerating influence of the metal, keeping 
the gaseous mixture below the temperature requisite for inflammation. Hence it was inferred, that if 
a mixture of hydrogen and oxygen, while condensed within a suitable receiver, was allowed to escape 
tlirough a capillary metallic tube, so as to form a jet, this might be made to burn without communica- 
ting ignition to the portion remaining in the receiver. 

By means of an apparatus contrived agreeably to this idea, Dr. Clark, of Cambridge, England, re 
peated the experiments, made many years before by Silliman and myself, without any other reference 
to ours, than such as was of a nature to do injustice. An exposition of the invalidity of Dr. Clark's 
pretensions to originality was made in Silliman's Journal for 1S20, voL ii., and in Tillock's Philosophi- 
cal Magazine for 1821, vol. lvii. 

The light produced by the hydro-oxygen flame with lime having been observed by Lieutenant Drum- 
mond, of the British Navy, was ingeniously proposed by him as the means of illumination in light 
houses, and has been, in consequence, subsequently used as a substitute for the solar rays, in an instru- 
ment known as the hydro-oxygen microscope, which is a modification of that wliieh has been called the 
solar microscope. The name of Drummond light has consequently been given to a mode of illumination, 
which I originally produced as above stated. 

The instrument which was used by Professor Silliman and by Bubens Peale, was that above described 
as having two perforations meeting in one. In this form it was, I believe, employed by Dr. Hope, ol 
Edinburgh, and Dr. Thompson, of Glasgow, who both treated it as my contrivance, anteriorly to the 
publication of Dr. Clark's memoir. 

The other form, consisting of two concentric pipes, was modified by a Mr. Mangham, with the view 
of producing a lime light for the microscope above alluded to. When I saw Mr. Mangham at the 
Adelaide gallery in 1S3G, he treated this instrument as mine, in another form. I was surprised after 
wards to learn that he had obtained a premium for this modification from the British Society for the 
Encouragement of Arts, without any allusion to the original inventor. 

After my return from Europe hi 1S36, 1 was very much in want of a piece of platinum of a certain 
weight, while many more scraps than were adequate to form such a piece were in my possession. 
This induced new efforts to extend the power of my blow-pipe ; and after many experiments, I suc- 
ceeded so as to fuse twenty-eight ounces of platinum into one mass. 

Although small lumps of platinum had been fused by many operators, with the hydro-oxygen blow- 
pipe, as well as myself, it had not, up to the year 1S37, been found sufficiently competent to enable 
artists to resort to this process. I am informed by Mr. Saxton, that some efforts which were made 
while he was in London were so little successful, that the project was abandoned. There was an 
impression that the metal was rendered less malleable when fused upon charcoal, as in the experiments 
alluded to. This is contradicted by my experiments, agreeably to which fused platinum is as malleable 
as the best specimens obtained by' the Wollaston process, and is less liable to flake. The celebrated 
Dr. lire, on seeing the platinum in the forms of wire, of leaf, and plate, said that there was no one in 
Europe who could fuse platinum in such masses. He also alleged that it had been found so difficult to 
weld platinum, that no resort was had to that process. In this I concur, having had the welding tried 
by a skilful smith, both with a forge heat, and with a heat given by the hydro-oxygen blow-pipe. An 
incorporation of two ingots was effected on their being hammered together, when heated nearly to 
fusion ; but on hammering the resulting mass cold, a separation took place along the joint by which the 
ingots were united. 

The difficulty seems to arise from the rapidity with which the platinum becomes refrigerated. It 
seems to have a less capacity for heat than iron, and, not burning hi the air as iron does, has not the 
benefit of the heat acquired by iron from its own combustion with atmospheric oxygen. 

Latterly, by means of the instrument and process which it is my object here to describe, I have been 
enabled to obtain malleable platinum from the ore directly, by the continued application of the flame. 
From some specimens of platinum I have procued as much as ninety per cent, of malleable metal 
The malleability is not inferior to that of the best specimens obtained, by reducing it to the state ol 
sponge, tlirough the agency of aqua regia and sal ammoniac. There is, however, a greater liability to 
tarnish, arising, probably, from the presence of a minute portion of palladium. 

Of the fusion of iridium and rhodium, I have already given an account in the Bulletin of the Society, 
ivliich was subsequently embodied in an article prepared for Silliman's Journal for October last, 184& 



It remains now to give an account of the apparatus employed in the fusion of platina on a large 

Fig. 211 represents the association of fifteen jet-pipes of platina with one large pipe, D B, at their 
upper ends, so that their bores communicate, by means of an appropriate brass casting, with that of the 
large pipe, the joints secured by hard solder. Their lower extremities are made to protrude about hall 
an inch from a box A, of cast brass, then- junctures, with the appropriate perforations severally made 
for them, being secured by silver solder. They come out obliquely in a line along one corner of the 
box, an interval of about a quarter of an inch alternating with each orifice. By means of flanges, the 
brass box is secured to a conical frustum of copper, Fig. 278, so as to form the bottom thereof, while 
she pipe, extending above the copper case, is screwed to a hollow cylinder of brass, A, Fig. 279, pro- 
vided with two nozzles and gallows screws g g for the attachment of appropriate hollow knobs, to which 
pipes are soldered, proceeding from the reservoirs of oxygen and hydrogen. Cocks are interposed by 
which to regulate the emission of the gases in due proportion. 

In connecting the pipes conveying the gases with the brass cylinder, A, Fig. 279, care should be 
taken to attach that conveying oxygen to the upper nozzle, while the other, conveying hydrogen, should 
be attached to the lower nozzle ; since, by these means, their great difference in density tends to pro- 
mote admixture, which, evidently, it must be advantageous to effect. 

The object of surrounding the jet-pipes with water, by means of the copper box,* is to secure them 
against being heated to such a degree as to cause the flame to retrocede and burn within them, so as 
finally to explode within the cylinder, A, g g, Fig. 279. It is preferable to add ice or snow to the 
water, in order to prevent undue heat. 

Fig. 280 represents a moveable platform, A, of cast-iron, wholly supported upon the point of the iron 
lever D B, which is curved towards the extremity under the platform, so as to point upwards, and to 
enter a small central conical cavity made for its reception. The lever is supported by a universal joint 
upon the fulcrum C, so that by means of tha sliding- weight at one end, the platform and its appurte- 
nances are counterpoised at the other. The platform is kept in a horizontal position by the cannon- 
ball, supported in a sort of iron stirrup terminating in a ring, in which the ball is placed. Upon the 
platform is situated an iron pan with a handle, holding the brick, on a cavity in which, as already 

* Since the engraving was made, I have preferred to use water-light boxes, with gallows screws and nozzles, situated 
cue near the bottom on one side, the other on the opposite side near tin; top. By means of the lower nozzle, a pipe is 
attached, communicating with a head of cold water, the other being so situated as to carry the water into a waste pipe, or 
large tub; a circulation ma}- lie kept up during the whole time that the operation is going on. 

As a support, a brick of kaolin is used, having an oblong elipsuidal depression on the upper face for the reception of the 
metal to bo fused. 



mentioned, the metal is supported The apparatus being duly prepared, and connected with the supply 
pipes, the hydrogen is first allowed to escape, and then the oxygen, until the ignition has attained 
apparently a maximum. The accomplishment of this object may, of course, require the adjustment of 
either cock several times, especially where there is any decline in the pressure either of the one or the 
other gas in its appropriate reservoir. 

By means of the handles of the lever and of the pan, the operator is enabled to bring the metal into 
the position most favorable for the influence of the heat, while his hands and face are sufficiently re- 
mote to render the process supportable. In fusing any quantity, not being more than four ounces, 
the platform may be dispensed with, the handle of the pan being held in one hand of the operator, 
while by the other the cocks may be adjusted. 

"When the blow-pipe of fifteen jets, or any larger, may be employed, and the platform is necessarily 
resorted to, the cocks must be adjusted by an assistant. 

Fig. 281 represents a cask made of boiler-iron, three-sixteenths of an inch thick, so as to resist an 
euormous pressure. The joints are secured by riveting, as in constructing lu'gh-pressure boilers. 

% jilL.ji" 

Tliis cask communicates with the hydrant-pipes, so called, by which our city is supplied with water, 
of which the pressure varies from a half to more than two atmospheres, say from seven to thirty 
pounds per-square inch, according to the number and bore of the cocks from which the water may be 
flowing at the time, for the consumption of the community. Hence, experiments, while using this 
head, are best made towards bedtime, or between that time and sunrise. The vessel is filled with 
water by opening a cock F on one side of the pipe C, and allowing the air to escape through the 
valve-cocks B. Being thus supplied, the cock F closed, and a communication with a bell-glass, into 
which oxygen is proceeding from a generating apparatus, being made by means of a flexible leaden tube, 
on opening the valve-cock B and the cock E the water will run out, and be replaced by gas from the 
bell This process being continued till the iron cask is sufficiently supplied with gas, the cock E must 
be shut. Whenever the gas is wanted for the supply of the blow-pipe, it is only necessary to establish 
a communication between the valve-cock B and the upper gallows-screw, Fig. 279, of the cylinder A, and 
to open the cock F so as to admit the water to press upon the gas, the efflux being regulated by B, or 
preferably by a cock of the ordinary construction, one of which kind should be interposed at a con- 
venient position between the valve-cock B and cylinder A. 

T represents a glass tube, which, by due communication with the interior, shows the height of the 
water, and consequently the quantity of gas in the vessel. 

G H represents a gaging apparatus, consisting of a cast-iron flask, of about a half a pint in con- 
tent, and a glass tube of about a quarter of an inch in bore, which should be at least five feet in height. 
The tube is secured air-tight into the neck of the flask, so as to reach nearly to the bottom within. 
The flask is nearly full of mercury. Under these circumstances, when a communication is made, by a 
leaden pipe between the cavity of the flask and that of the reservoir, an equilibrium of pressure re- 
sulting, the extent of the pressure is indicated by the rise of the mercury in the tube. 



In order to generate hydrogen for the supply of a reservoir like that represented by the preceding 
figure, I have employed the vessel representei 1 by Fig. 282. This vessel, by means of a suitable aperture, 
susceptible of being closed by a screw-plug, is half filled with diluted sulphuric acid. Being famished 
with a tray of sheet copper D, punctured like a coal-sieve, and supported by a copper sliding-rod E, 
strips of zinc are introduced in quantity equal to the capacity of the tray. The sliding-rod passes 
tluough a stuffing-box F, at top of the reservoir, so that the operator may, by lowering or raising the 
tray, regulate or suspend the reaction between the zinc and its solvent, accordingly as the supply of 
hvdrogen is to be produced, suspended, increased, or diminished. 

The communication with the reservoir is cpened and regulated by means of the cock P, furnished 
with a gallows-screw G for the attachment of a leaden pipe, as above described, in the process foi 
supplying the reservoir with oxygen. 

Another apparatus for producing a supply of hydrogen, is represented in Fig. 000. It consists of two 

similar vessels of boiler-iron, eacli capable of holding forty gallons. They are lined internally With 
:opper, being situated upon a wooden frame, so that the bottom of one is two-thirds as high as the top 
of the other. The upper portion of these vessels communicate by a leaden pipe B, of about half an 
inch bore, furnished with a cock, while the lower portions communicate by another leaden pipe of a 
bore of 1 J inches. 

The upper vessel is surmounted by a globular copper vessel, of about twelve inches in diamei er 
which, from its construction, renders it possible to introduce an additional supply of concentrated acid 
while the apparatus is in operation, without reducing the pressure within the reservoir, by permitting 
Ihe excese above the pressure of the atmosphere to escape. This object is accomplished as follows ■"- 


The valve at the end of the rod, attached to the lever L, being kept shut by the catch SI, the screw- 
plug H removed, the acid is introduced through the aperture thus opened. In the next place, the 
plug being replaced, and the valve depressed by means of the lever and rod, so as no longer to 
close the opening, which it had occupied, the acid descends from the chamber into the cavity of the 
vessel beneath it. The valve is of course restored to its previous position as soon as the acid has 
effected its descen. 4 . 

The lowermost vessel is furnished with a perforated copper tray, supported by a copper sliding-rod, 
in a way quite analogous to that already described in the case of the copper reservoir. It is also sup- 
plied with zinc and its solvent in like manner, being made half full of the diluted sulphuric acid. Of 
course, on contact being produced between the zinc and its solvent, the generation of hydrogen will 
take place. So long as the communication between the upper portions of the two vessels is open, the 
gas will extend itself into both, occupying the whole of the upper vessel, and that half of the lower 
one which is unoccupied by the liquid. But if, in this way, the pressure reaches to two atmospheres, 
as indicated by the gage, on shutting the communication tlu-ough the pipe B, the pressure in the in- 
ferior vessel will augment, that in the superior vessel remaining as before, but the liquid wdl conse- 
quently begin to pass out of the inferior vessel through the pipe A, and thus may lessen the contact 
between the acid and zinc, and finally suspend it altogether. Meanwliile the gas in the upper vessel 
being condensed to nearly half its previous bulk, the pressure will be nearly four atmospheres. It 
will, in fact, always be nearly double that which existed before the pipe B was closed. 

In order that nearly the whole of the acid shall be expelled from the inferior vessel, the tray must be 
depressed till it touches the bottom of that vessel. 

The pressure being four' atmospheres at commencement, as soon as, by means of a pipe attached to 
the valve-cock N, an escape of gas is allowed, the acid is forced again upon the zinc, and thus prevents 
a decline of pressure to any extent sufficiently to interfere with the process. 

The gases may be used from a receiver in which they exist, in due proportion, safely by the following 
means. Two safety-tubes are to be made, not by Hemming's process exactly, but as follows : — A cop- 
per tube, silver soldered, of wliich the metal is about the eighth of an inch in thickness, is stuffed 
with the finest copper wire, great care being taken to have the filaments straight and parallel The 
tube is then to be subjected to the wire-chawing apparatus, so as to compress the tube on its contents 
until the draught becomes so hard, as that it cannot be pushed farther without annealing. The stuffed 
tube thus made is to be cut into segments, in lengths about equal to the diameter, by a fine saw. The 
surfaces of the sections are to be filed gently with a smooth file. By these means, they appear to the 
naked eye like the superfices of a solid metallic cylinder. Brass caps being fitted on these sections, 
they are to be interposed by soldering, at the distance of a foot or more, iuto the pipe for supplying 
the jet. Under these circumstances, the posterior section, becoming hot, may allow the frame to 
retrocede ; but the anterior section being beyond the reach of any possible combustion, and remaining 
cold, will not allow of the retrocession ; and as soon as the flame passes the first section, the operator, 
being warned, will of course close the cock, and subject the posterior section to refrigeration before 
proceeding again. 

But this plan of operating may be rendered still more secure by interposing a mercury bottle, or other 
suitable iron vessel, half full of oil of turpentine, between the reservoir and safety-tubes, as in the 
arrangement of a Woulfe's bottle. A leaden pipe proceeding from the reservoir is, by a gallows-screw, 
attached to an iron tube wliich descends into the bottle, so as that its orifice may be near the bottom. 
The leaden pipe communicating through the safety-tubes with the jet-pipe, is attached to the neck 01 
the bottle. Thus the gaseous mixture has to bubble through the oil of turpentine in order to proceed 
through the safety-tubes to the jet-pipe. If, while tliis process is going on, the flame should, by 
retrocession, reach the cavity of the bottle, exploding in contact with the turpentine, a compound is 
formed, wliich is, per se, inexplosi^e from the excess of carbonaceous matter. Meanwliile the shock, 
acting on the surface of the oil, drives it into the bore of the iron tube, and thus, both by its chemical and 
mechanical influence, renders it utterly impossible that the flame should reach the cavity of the reservoir. 

BOBBINET MACHINERY, is the name of macliines which are intended for manufacturing a 
peculiar net-like texture, whose constructive is inferred from that of the pillow-made or boie-lace, and 
wdiich, in its most simple intertwisting, is known by the name of plain bobbinet and quillings. The 
simple intertwisting of the plain bobbinet has been altered in various manners, and thus have been 
produced new kinds of texture, partly very different in appearance from that of the plain bobbinet ; 
and in recent time furnishing very fine fancy articles, much in demand. They are termed figured 
bobbinet in the following description, wdiich treats chiefly of the most common and most recent systems 
of bobbinet machines. 

The macliines for manufacturing quillings, and which are known by the term stripe-machines, work 
quillings or edgings from J to 4 and 6 inches in breadth, and of considerable length. A great many 
edgings, connected with and by the side of each other, thus forming one broad piece, are worked 
simultaneously, and are subsequently separated. As the quillings are, as it were, to be edged at both 
borders, for the sake of fastness and durability, this edging and intertwisting of the several quillings 
require particular contrivances in the machines, which thus, according to the different systems applied 
to them, are more or less complicated 

Those for manufacturing the figured bobbinet are in general narrow ; that is to say, there can be 
worked only pieces of inconsiderable breadth by them. 

Tliis is owing partly to the circumstance, that older macliines, originally intended for manufacturing 
pieces six or eight quarters of a yard wide, have been arranged for figured bobbinet, to make them 
still fit for use in any way ; and partly to the fact that the making of figured bobbinet is by far more 
difficult than that of plain bobbinet, and that it requires the most eager attention and skilfulness of the 
operative. To the atter it would be almost impossible to overlook broad pieces of tliis kind, or the 
work would go on so slowdy that such an arrangement could be of no great avail 



Alphabetical Survey and Explanation of the Letters in the Figs. 284 to 394. 

A, right side-frame, Figs. 285 and 286. 

A„ left side-frame, Figs. 284, 286, and 287. 

B, fore front-frame, Figs. 284, 303, 317. 
Bi, back front-frame, Figs. 284, 303, 317. 

0, joist joining the uppermost parts of the side-frames, Fig. 286. 

Ci, pillars screwed on C, and bearing the sockets of the lace-beam A, Fig. 286. 

D, rounded iron bars across which the texture passes on its way to the lace-beam, Fig. 286. 

5 1 ' \ cross-beams at the right and left sides of the frame, Figs. 284 and 285. 

E, front pusher-bar. Figs. 284, 2S8, and 289. 
E„ back pusher-bar, Figs. 284, 288, and 289. 

F, a kind of reed composed of perforated brasses for tlie warp-threads, Figs. 284 and 286. 
F|, steel springs of the hold-fast contrivance, Fig. 357. 

G, warp-beam, Fig. 284. 

?» [ lever-arms of the point-bars, Figs. 234, 285, 288, and 289. 

H, lever bearing the weight-stone R, Figs. 284, 286, and 287. 

H,, lever moving the front point-bar, Fig. 287. 

H,., lever moving the back point-bar, Figs. 287, 288, and 289. 

1, cradle-arms, Figs. 284, 285, and 286. 
I,, cradle-pieces, Figs. 284, 2S5, and 2S6. 

K front bolt-bar, Figs. 2S6, 28S, 289, 300, and 303. 

K„ back bolt-bar, Figs. 287, 2SS, 2S9, and 303. 

L, front comb, Figs. 284, 2SS, and 2S9. 

L„ back comb, Figs. 284, 2S8, and 2S9. 

M, front point-bar, Figs. 284, 285, 288, 289. 

N, back point-bar, Figs. 284, 285, 288, and 289. 

N , crowbar of the front point-bar, Figs. 286 and 287. 

Ni, crowbar of the back point-bar, Figs. 288 and 289. 

O, socket-frame in the midst of the machine. ) Both are fastened to B and B>, and bear the sockets 

P, socket-frame at the side of the machine. \ of the lockers, Figs. 315 and 317. 

P„ forked bars for both point-bars, Figs. 287, 288. and 289. 

Q, weight-stone for the tension of the warp, Figs. 284, 2S5, 286, and 287. 

Q|, lifting-thumb acting on the forked bar P„ Figs. 288 and 289. 

R, grooved disks for the cords or strings S, Fig. 286. 

Ri, large rowels, Fig. 284. 

R 5 , shell-wheel of the front point-bar, Fig. 286. 

R„ shell-wheel of the back point-bar, Figs. 286, 288, and 2S9. 

S, cords or strings for the tension of the warp, Figs. 284, 285, 286, and 2S7. 

S,, support of the front point-bar, Fig. 2S7. 

S„, support of the back point-bar, Figs. 287, 2S8, and 2S9. 

![,' I shafts to winch the lever-arms G, and G 2 are fastened, Figs. 284, 288, and 289. 

U, large heart-shaped disk to bring about the swinging movement of the pusher-bars, Figs. 284, 288, 
£89, and 290. 

Ui, similar disk in Figs. 358 and 859. 

V, great spur-wheel with 48 cogs at the principal axis W, Figs. 285 and 286. 

W, principal axis of the machine, Figs. 284, 286, 288, and 289. 

W 1 , driving axis of the maclunery for the thong-disk Y, Figs. 2S4, 285, and 2S7. 

X, dented wheel at the axis W t , with 36 cogs, Fig. 285. 

Y, thong-disk at the axis W,, Fig. 286. 

Y„ thong of the disk Y, Fig. 2S6. 

Z, the lace-beam, Fig. 2S4. 

a, front guide-bar, Figs. 284, 331, 332, 303, 317, &c. 

a l} adjusting screw for the lateral movement of the front guide-bar, Figs. 331, 332, and 333. 

a 2 , adjusting screw for the lateral movement of the back guide-bar, Fig. 333. 

A, back guide-bar, Figs. 284, 303, 315, 317, and 333. 

■ " V curved stays through which the adjusting screws a and a 3 pass, Figs. 331 and 333. 

63, common pivot of the levers H and H 2 , and of the crowbar N and Nj, Figs. 2S7, 288, and 289. 

c, front series of guides, Fig. 284. 

Ci, projecting bolt, through which the supporting screws d and d Q pass, Figs. 331 and 333. 

C! ' [ adjusting screws of the levers H, and H a , Fig. 2S7. 

C 3, > 

d, back series of guides, Fig. 284. 

j 1 ' > supporting screws of the guide-bars, Figs. 331, 333. 

e, middle stay of the bolt-bars, Figs. 300, 301, 302. 
/, warp-threads, Figs. 284, 335, 336, and 360. 


/,, steel springs for pushing back the guide-bars, Figs. 285, 295. 

/j, pivots on which the point-bars turn, Figs. 2S5, 288, 289. 

a, socket-irons of the warp-beam, Fig. 284. 

9 " \ leTer-bars for the lockers, Figs. 285, 2SS, and 289. 

h, lever-arm at the midst of the axis w, Figs. 358 and 359. 

{'" I lever-arms at the ends of the axis w, Figs. 35S, 359, and 284, 2S5, 288, 289. 

K ) 

i, pivot of the lever-bars y, and g % Figs. 2S4, 2S5, 2SS, 289. 

£' [weft-threads, Fig. 360. 

k 2 , curved arms, to which the pivots f, of the point-bars are fixed, Figs. 285, 28S, 289. 

/, front carriage-line, Figs. 284, 28S, 289. 

/„ back carriage-line, Figs. 284, 28S, 2S9. 

/„, sockets of the shafts T and T„ Figs. 2S5, 286. 

/ a , sockets of the shafts w in Figs. 358, 359. 

'"' ] drawer-bars of the lever-arms h, and ha, Figs. 358, 359, and 284, 285, 2S6, 288. 

mi, ) ° 

»i 2 , adjusting screw for the lateral movement of the front comb, Figs. 286, 300, 301. 

m^, adjusting screw for fixing the back comb. Figs. 2S6, 288, 300, 301. 

n, point-pieces, Figs. 2S4, 2S6, 2SS, 2S9. 

"" ,' split sockets of the guide-bars, Figs. 304, 305 a, in the midst of D, and D 2 , and of the machine. 

fis, spiral-spring of the point-bars, Fig. 285. 

0, comb-shifting disk at the shaft t, Fig. 286. 

o„ ratchet-wheel of the front guide-bar, Fig. 2S6, left side. 

Os, ratchet-wheel of the back guide-bar, Figs. 285. 2S6. 

o 3 , comb-shifting disk at the shaft t, right side, Fig. 286. 

p, locker-bar, Figs. 284, 2S8, 289, 309. 

p it bolts or rails to which the adjusting screws in, and m 3 are fixed, Figs. 300, 301, 2S6. 

y>2, socket-pieces at Di and D 2 , Figs. 2S4, 285, 286. 

q, locker, Figs. 284, 288, 289, 309. 

q t , supporting arms or stays of the bolt-bars, Figs. 284, 285, 287, 300, 301, 302, 303 

y 2 , screws for supporting the bolt-bars, Fig. 317. 

r, sliding roller of the large heart-shaped disk IX, Figs. 284, 2S8, 2S9 

(r,) sliding roller of the large heart-shaped disk Ui, in Figs. 358 and 359. 

r,, roller of the locker-disk vi, Fig. 286. 

r s , roller of the locker-disk i' 2 , Fig. 2S6. 

r 3 , rowels at the bar D, Fig. 286. 

r s , sliding roller of the shell-wheels R^ and R 3 , Figs. 2SS and 289. 

s, arms by which the point-bars are connected witli the supporting bars Si and Sa, Figs. 287, 288, 285 

s " \ dented wheels at the axis W, Fig. 2S6. 

1, shafts to which are fixed all ratchet-wheels and disks, Figs. 285, 286, 2SS, 289. 

'" I dented wheels at the axis t, Fig. 286. 

;(, pivot on which the pushing levers X\ and x 2 move, Fig. 285. 

!<„ angular lever of the front guide-bars, Fig. 295. 

iii, angular lever of the back guide-bars, Fig. 295. 

!i 3 , pushing lever of the front comb, to the right, ) y^ „„. 

u„ pushing lever of the front comb, to the left, $ °' ' 

v, motive power or quarter-wheel of the lockers. Figs. 284, 311, 312. 

»',, locker-disk for the back locker, at the axis W, Fig. 286. 

« a , locker-disk for the front locker, at the same axis, Figs. 2S4, 2S6, 28S, 289. 

if, shafts to which the lever-arms h, A, and A 2 , are fixed, Figs. 386, 289, 358 and 359. 

«i, shafts to which the cradle-arms I, and cradle-pieces I, are fixed, Figs. 284, 285, 2S6, 287. 

t'-v, dented wheel of the lace-beam, Fig. 285. 

x, socket of the sliaft w, Fig. 284. 

Xi, pushing lever of the front, guide-bar, ) ,-,. „„,, , , 1n . 

s* pushing lever of the back guide-bar! \ ^ 286 and 29i> - 

j" |- angular levers for pushing the bolt-bars, Figs. 285 and 287. 

y, bolt or rail, through which the common peg of the angular levers «, and u % are put, Fig. 295. 
;/„ adjusting screw of the point-bar, on which the upper fork of the bar Si is acting, Figs. 288, 28*. 
i/i, adjusting screws of the point-bar, which strike against the side-frame A and Ai, Fig. 285. 
z, a trigger, Fig. 286. 

z " \ dented bars for the lockers, Figs. 284, 237, 311, 312, 314. 

a, foot-screws of the bolt-bars, Figs. 284, 2S5, 286, 287, 300, 303. 
fS, notch in which the middle stays e are running, Fig. 317. 
a 1 
' r iron pegs at the lower fork of the bar S,, Figs. 2SS and 289. 

' ' 7 
























Machines for manufacturing broad plain Bobbinet. 

The latest and most approved construction of these machines is according to the double-locker sys 
tem. Machines of this system can be arranged for any breadth of the piece, and are working foi 
weeks, and even months, with great precision and quickness, without any interruption which might 
be produced by irregularity in the mechanism.. Being commonly of considerable breadth, the motive 
power must be very strong ; therefore it is driven either by water or steam. 

In the following, we give a description of a machine for webs 8 quarters wide, constructed according 
tc the double-locker system, and illustrated by Figs. 284 to 375, in the most careful manner. The illus- 
trations are given with all particulars required, winch may enable the mechanic to draw upon a large 
wale from them. 

The machine for manufacturing plain bobbinet, though being the most simple of all bobbinet 
machines, belongs, however, by its construction to the most complicated ones. Its web is represented 
by Fig. 360 on a large scale. One and the same thread is marked along its way by the same letter. 
The threads f are extended up and down, or proceed downwards in serpentine lines, while the two 
other sets of tlireads !c and &, proceed from the right to the left, and from the left to the right in 
slanting directions. By this, the twisting and interlacing of the threads is produced. The perpendicular 
threads in the figure, which are parallel to the border, may be regarded as the warp, and the two sets 
of slanting threads as the weft, in comparing bobbinet with a common web. The straight warp- 
threads receive their twist from the tension of the weft-threads, twisted obliquely round them alter- 
nately to the right and left. 

This seemingly simple union of the threads requires, however, a very complicated mechanism, which 
must be understood before the operation of the machines can be comprehended, and then- result ex- 
amined more closely. 

At the chief frame A A, B B, C, are shown all parts' of the machine. (See Figs. 284 to 287.) Fig. 
284 shows the machine near its centre in transverse section; Fig. 2S5 gives an end view of the right 
Bide of the machine, before which the operative has liis ordinary place. Fig. 286 gives a front view of 
the fore side, and Fig. 287 an end view of the left side. 

Two and two opposite sides of the frame are completely equal to each other, viz : A and A„ B and 
Bi ; all four are united by screw-bolts. The joist C, Figs. 2S4 and 286, binds the upper ends of A, A 1 

The warp of the web consists, as has already been mentioned, of parallel running warp-threads, 
which are coiled round the warp-beam. In proportion to the proceeding of the fabrication, the warp is 
unwound, while at the same time the finished lace is wound upon the lace-beam. The lace-beam is 
placed above the warp-beam, as may be seen by Z and Q in Fig. 284, where they are shown in trans- 
verse section. 

The ends of the warp-beam (represented in Fig. 284, in transverse section, and with the warp wound 
apou it) are provided with strong rollers or disks ; and its pivots run in iron sockets, which are fastened 
io B„ and in the figure marked by g. The disks R are grooved to receive the cord S, one end of 
which is Aasiened at B, while the other end runs vertically downwards, and is fastened to the lever H. 

This lever turns on a pivot at the post Bi, and its fore end bears the weight Q. This contrivance 
serves to keep the warp in due tension while being wound off the warp-beam. This unwinding takes 
place hi four rows of warp-threads, (see Fig. 2S4,) for which purpose the single threads pass the eyes 
of a kind of reed F. Figs. 284, 286, and 350, 351, consisting of single pieces of latten-plate, called brasses, 
and placed one by one into the grooves of two long staves, bound together at the ends and in the midst. 
The brasses are regularly perforated in four rows. The reed is oblique, and close above the warp- 
beam loosely fastened, (see Figs. 2S4 and 351.) that it (if required) may be lifted a little, and not slip 
down. The warp-threads are marked with/. Fig. 350 gives the view of a brass ; Fig. 350 a trans- 
verse section of a row of eyes ; and Fig. 351. 

The fourfold divided warp passes vertically upwards between two parallel guide-bars, and unites 
close above them into two series of warp-threads, two and two series of the warp being drawn into two 
series of guides. The guide-bars (see Figs. 284, 286, 330, 331, 332, 333, 334, 335, 336, 337) are placed 
along the whole machine and supported at both ends and in the centre, that they may retain their 
parallel situation and their relative position. They are in all figures marked with a and b — a marking 
the front and 6 the back guide-bar. Both guide-bars are liable to lateral movement, by which a 
lateral shifting of the warp is effected. The series of guides c and d consist, like the reed F, of single 
pieces put together lengthwise. The number of the pieces, which are to be of entirely equal breadth, 
depends upon the number of the warp-threads, or of the breadth of the texture. 

Every single piece, consisting of a mixture of lead and zinc, is provided with an equal number oi 
guides, being made of iron or steel wire, and cast together with the pieces in uniform distance from 
each other. Fig. 334 gives a front view of a single lead-piece in its position when screwed to the guide 
bar; Fig. 335 a side view of it; Fig. 336 represents a single guide; and Fig. 337 an ear. Guides are 
almost exclusively used, as by them the drawing in of the warp-threads is considerably facilitated. 

The two series of guides c and d divide the warp into two opposite equal parts, of which the texture 
is to be made. At the point where the texture begins both unite in one warp and are placed in one 
plane. Each half extends over the whole breadth of the texture, the threads of each series having 
double the distance between themselves, apparent in the texture. 

Tliis arrangement is of the greatest importance. The lace-weaving is facilitated by it, and at the 
same time some parts can be made stronger, which is of great avail regarding durability and quickness 
of operation. Moreover, the inconvenience of entangling and tearing the threads is removed. 

The texture begins near M N, where the interlacing and twisting of the warp and weft threads is 

Fig. 360 shows the formation of the regular holes or meshes, completed by the round points of the 
point-bars M and N, after the intertwisting of the warp and weft threads having been accomplished 


below. The formation of the meshes is effected round the points of the point-bars, and simultaneouslj 
across the whole breadth of the warp in horizontal lines. For the formation of one row of meshes only 
one point-bar is required. Both alternate in this operation, so that one point-bar holds the finished row 
of meshes, whde the other takes up the next following, and thus they relieve each other continually. 

In proportion to the proceeding of the formation of the rows of meshes, the texture is wound upon 
the lace-beam. Figs. 284, 285, 286, 287, 28S, 289, S21, 322, S2S, and 329, will illustrate what is saic 

The point-bars are marked with JI and X", — the front bar with II, and the back point-bar with N 
Both are provided with points which are adapted to each other. 

The points are cast in lead-pieces which are fixed to the point-bars by screws, (see Figs. 321, 322 
and 32S, 329;) the last-mentioned figure shows a point-piece N separately. Every point-piece mus 
have exactly the same breadth as the lead-pieces of the series of guides c and d, whose number is equa 
to that of the point-pieces. The number of points in each point-piece is likewise equal to that of the 
guides in each lead-piece. By Fig. 328, it will be perceived that between the single points there is 
room enough not only for the opposite points, but also for the intertwisting threads. 

Z represents the lacs-beam, running parallel with the warp-beam, and being of equal length, and oi 
equal or smaller diameter. It turns on pivots, whose sockets are placed in similar manner to those of 
the warp-beam. See Fig. 2S6. 

The successive turning of the lace-beam is effected by a regulator, moved by the macliinery. 

The finished lace passes on its way from the point-bars to the lace-beam across the rounded iron bar 
D, Figs. 284, 286, 352, 353, and 354, which serves to support the texture. At both ends of it are 
rowels r 3 (355) turning on small pivots. The pricks of these rowels enter the meshes close by the borders 
of the texture, thus preventing its running together. The larger rowels R„ close above the smaller ones, 
are intended for the same purpose. 

The lace is, by its winding upon the lace-beam, on account of its tension, somewhat less broad than it 
is when lying on the point-bars. 

The union of the warp and weft takes place below II X', and is effected by two rows of weft-threads, 
each of which is wound round a small bobbin, that passes between two and two warp-threads. Thus 
there are two rows of bobbins which are moved round the warps; and in this way the intertwisting is 
effected. The bobbin-rows stand parallel with the breadth of the warp, and either both rows before or 
behind it ; or one row before and one behind it. 

That the bobbins may occupy these respective positions, they are pushed from one side to the ether 
on carriages and bolts. Each bobbin has its separate carriage and bolt ; and two and two bobbins are 
with their carriages behind each other, on one bolt. The whole series of bolts is called a comb. 

The bobbins, carriages, and bolts, are of a peculiar shape, as may be seen by Figs. 284, 2S6, 2SS, 289 
•96, 297, 298, 306, 307, 30S, 326, 33S, 339. 

Fig. 296, gives the side view of a carriage with inserted bobbin. 

Fig. 297, section of a bobbin. 

Fig. 29S, carriage viewed from the other side, and without the bobbin. 

Fig. 299, section. 

Figs. 306, 307,, and S08 b , show a bolt. 

Fig. 806, gives a side view of the bolt, when placed in the machine. 

Fig. 307„ represents its lower edge turned towards the warp. 

Fig. 308„, gives a section of the bolt at its opposite end. 

The single bolts are, like the points and guides, cast in lead-pieces, each of which contains as many 
bolts as there are points and guides in one lead-piece. The breadth of the comb-pieces is exactly equal 
to that of the other lead-pieces. 

Figs. 338. (view from behind,) 339, (front view.) and 326, (side view,) represent a comb-piece. 

The small interstices between the single bolts receive the carriages, which thus, with their grooves, 
are placed upon the bolts. See Figs. 298, 299, 306, 326, 338, and 339. 

The bolt-pieces are by the side of each other screwed on a bar, and thus form together the comb. 

One of such combs is placed before, and one behind the warp, and the distance between both is not 
greater than required for the easy passage of the double row of warp-threads. 

The bolts of both combs are exactly opposite each other, that the carriages may be pushed from one 
comb to the other without obstruction. 

The bolts are circular, to keep the bobbin-threads at an equal tension, while the carriages are pushed 
to and fro. 

The width of the carriages, compared with the inconsiderable distance by wliich then- bolts stand off, 
on both sides of the warp, permits this pusliing from one comb to the other without any difficulty. Botli 
combs have their correct mutual position with reference to the centre of the circular line. 

In the figures, the front comb is marked with L, and the back comb with 1^ ; the bars on which the 
limbs are screwed, and which are called bolt-bars, are marked with K and K„ and the carriage-lines 
\rith I and l v The carriage-line I, which is always nearest to the operative, is called the front, and .'j the 
bick line. For this reason they use to say front and back carriage-thread series, or briefly front and back 
carriage-threads, instead of bobbin-thread series, etc. 

The unwinding of the threads and turning motion of the bobbins, is to be seen by Figs. 296, 297, 29S, 
and 299. 

The swinging movement of the carriages on their circular bolts is not a continual one, but is made in 
short regular intervals. The pauses occur as soon as the carriage-lines, coming from the one or the other 
side, have passed the warp-threads and stand completely on their bolts. Meanwhile the shifting of the 
warp-threads (not being hindered now by the carriages) to the right or to the left takes place. As soon 
as the carriages pass the warp-threads, the regular twisting and crossing is accomplished, and at the 
same time the mesh of net completed 


The swinging movement of the carriages is effected in the following manner. See Figs. 284, 288, and 

E and E 1 are two bars, parallel to the carriage-lines, but somewhat longer, and their oblique side 
turned towards them. 

Both bars are, with their ends, placed so that they cannot shift their places. Figs. 2S4, 2S8, and 2S9 
show the different positions which they occupy. They are close above the comb, seize the carriages, 
and push them from one comb to the other, as soon as put in a swinging motion. 

This motion is in consequence of their moveable sockets being put in the rifts of the cradle-pieces I,, 
which are moved backwards and forwards like a pendulum. See Figs. 2S4, 285, 286, 287, 340 to 

By Figs. 2S4 and 289, it may be seen that these pusher-bars never can pass the centre, but stop at 
some distance from the warp before they make their retrograde motion. Thus the puslring of the car- 
riages beyond the midst, cannot be effected by them ; this must be done by the drawer-bars, or the blades 
of the locker, (here called double-locker.) These are marked with q, and the locker-bar on which they 
are screwed, with p. Fig. 294 gives a transverse section of the double locker-blades. The locker-bars 
p are placed at both sides of the warps below the comb, towards the bolts of the carriages. The locker- 
Dlades may be cast either each separately, or, more properly, both together, and then fastened to the 
locker-bar by screws. Their material is brass, but the bars are made of wrought-iron. The length of 
the combined locker-blades is somewhat exceeding that of the comb, and they therefore can seize a whole 
carriage-line at the pointed ends of the carriages projecting from beneath the comb. See Figs. 2S4, 288, 
2S9, 296, and 298. By a slight angular movement of the blades, the carriages, pushed to them by the 
pusher-bars, are seized at their feet, and drawn across the midst of the machine through the warp-threads. 
The movements of the pusher-bars and lockers are thus supporting each other, and by this, the swinging 
of the carriages is completely effected. The lockers serve at the same time to keep back the carriage- 
lines during the above-mentioned pauses, thus prevent them getting into the centre, and bringing the 
warp-threads out of order during their shifting. The periodic angular movement of the locker is effected 
by motive power, dented bars and eccentric disks acting upon the axis of the locker-bars. Figs. 284, 
2S8, and 289 will more distinctly explain the operations of the single locker-blades. 

In Fig. 284, both carriage-lines stand on the back comb. The front Made of the back locker holds the 
hind-feet of the front carriage-line, and thus retains also the back carriage line. The front locker is com- 
pletely turned over, so that its blades by no means hinder the carriages from sliding on the front comb. 
In Fig. 285, the front blade of the front locker has already drawn over the front carriage-line, and keeps 
it on the comb. The back carriage-line is on the back comb, and is retained there by a blade of the 
back locker. 

In Fig. 2S6, both carriage-lines are on the front comb, and the back line, together with the front car- 
riage-line, is retained by tb.3 back locker-blade. The figures also show the counter-movement of both 
lockers, the necessity of the removal and height of the locker-blades, etc. This highly ingenious con- 
trivance is invented by Jlr. llorley. 

The chief parts of the macliine, their movements and functions in general, are now known, and it w ill 
hereafter not be difficult more to follow the movements, operations, and connection. But first, a stand- 
point must be afforded, from which the whole progress of the machine can be overlooked. For this pur- 
pose, it will be suitable to commence with the moment when a row of meshes is completed and seized 
by the point-bars, and at the same time to notice the particulars concerning the rotation of the shafts, 
wheels, and disks. 

The great dented wheel V (with 48 cogs) at the principal axis W, makes three rotations during the two 
movement-periods, in which two rows of meshes are completed. It is the same with the two dented 
wheels s, and s 2 . 

The large heart-shaped disk TJ, and the two small locker-disks », and r 2 make likewise three rotations 
in tins time. Each rotation of these disks brings about four interrupted movements of the pushing and 
locker bars. Every such movement causes a carriage-line to cross a comb. Consequently, for completing 
one row of meshes, six movements of carriage-lines are required. 

The dented wheels t t and (.,, (of the axis t,) which are turned by s, and s«, have thrice as many cogs as 
the latter dented wheels, and, for this reason, they make only one rotation, while the principal axis W 
makes three. It is the same with the shafts t, and the pushing-wheels and lifting-thumbs connected 
with them. 

The notches and elevations of the pushing or notched wheels, occupy nearly one-twelfth of the pe- 
riphery, if taken together. 

In Figs. 345, 346, 847, and 348, their mutual position with reference to their notches and elevations is 
shown, as they must be put on the shafts. This position corresponds to the moment which is represented 
in the figure of the machines, in Figs. 284, 285, 2S6, and 2S7. The disks move in the direction of the 

The pushing-points of the levers are in a vertical plane going through the axis of the shafts t. Equally 
marked points of the periphery of the pushing or ratchet wheels are during the movement entering this 
vertical plane, and acting upon their levers simultaneously. 

The ratchet wheels in Figs. 345 and 346, are, during a total rotation of the axis, (or during the com 
pletion of two rows of meshes,) pushing the front comb twice to the right and twice to the left ; the 
notched wheel o„ Fig. 347, pushes in the same time the front guide-bar, and with it the front half of the 
warp, thrice to the right and to the left, and the notched wheel o», Fig. 348, does the same with the 
back guide-bar and the back half of the waip. 

The shell-wheel R, of the front point-bar (represented in Fig. 287, but omitted in Figs. 28S and 289) 
has a position entirely opposed to that of R 3 , so that the indenture of the shell-wheel R 2 stands deepest 
while that of R., stands highest. (See Fig. 289.) 

The points 9. 10, and 11, of the lifting-thumb (& u (see Figs. 28S and 289,) are, with reference to the 


simultaneous pushing of the ratchet-wheels, corresponding about the points 20, 22, and 12 ; that is to 
say, as soon as the points 9, 10, and 11 are active, the points 20, 22, and 12 follow tliis movement in 
succession. On the other hand, the edge of the indenture in the shell-wheel R, corresponds respectively 
with 10 and about 16, its centre with 11 and IS, and its opposite edge with 19. The corresponding 
points of R 3 are respectively 10, and about 22, then 11, 12, and 13. 

The relative position of all parts being thus correctly stated, we shall follow the various movements 
from the moment when a row of meshes has jilst been completed, and the points are falling or catching 
in the meshes. 

Fig. 289 shows the positions of most of the chief parts in this movement; and there we see ^jrhat 
follows : — ■ 

The back point-bar is about to fall off. Both carriage-lines are on the front comb. The front half of 
the warp assumes its usual position, (that is to say, its most frequent position.) Point 1 2 on o, is under 
the point of the lever x t , (see Fig. 2S6.) 

The back half of the warp has just now shifted from the left to the right, the lever x? being fallen off 
from 12 on o 3 . 

The movement ensues. The back point-bar N lifts the row of meshes. The back carriage-line /, goes 
up to the back comb. 

After the shafts t and TV" have made respectively one-twelfth and a quarter of rotation, a pause 

The point-bars have lifted up their rows of meshes almost entirely. 

The back carriage-line is on the back comb. All carriages have made a comb-movement. 

The front half of the warp retains its usual position, (see above ;) the point 13 on o s is advanced until 
beneath the point of the lever. 

The back half of the warp lias shifted from the right to the left, (the pushing-lever x 2 has risen above 
the prominence at 13 on o 2l ) and assumes its usual position, (see above.) 

The first movement is accomplished ; and the different parts are in the position of Fig. 2S8. 

The second movement begins. The point-bars are at rest. 

The front carriage-line goes up to the back comb, where the back carriage-line moves higher up. 

The shafts t and W make, respectively, one-twelfth and a quarter of rotation, and a pause ensues. 

Both carriage-lines are on the back comb. 

The front comb is pushed from the right to the left, the points 14 of o and o 2 , being advanced to be- 
neath the points of the levers. 

The front half of the warp has shifted from the right to the left. 

The back half of the warp retains its usual position. 

The point-bars are at rest. 

The second movement is accomplished. 

The positions of the different parts represented in the figures, (with the exception of Figs. 28S ana 
89,) are corresponding to this moment. 

The third movement begins. 

The front carriage-line I returns to the front comb. 

The frout point-bar begins to leave its row of meshes. This curve from 9 to 10 of the lifting-thumb 
acts upon the pin of the fork. 

The shafts t make again one-twelfth of their rotation, and the pause ensues. 

The front carriage-line is on the front comb, and has moved from the left to the right. The back 
carriage-line is on the back comb. 

The front half of the warp has shifted from the left to the right, and is in its usual position, as is the 
back half also. 

The front point-bar is lifted almost entirely out of the meshes. 

The third movement is accomplished. 

The fourth movement begins. 

The back carriage-line goes up to the front comb. 

The front point-bar is lifted out. 

The shafts t make their fourth twelfth of the rotation, and the pause ensues. 

Both carriage-lines are on the front comb, and move from the right to the left. 

The front and back parts of the warp are in their usual position. 

The front point-bar is about to lower. 

The fourth movement is accomplished. 

The fifth movement begins. 

The back carriage-line returns to the back comb. 

The point-bar lowers. The fifth twelfth of the rotation of the shafts t is made, and the pause 

The back carriage -line is on the back comb. 

The front carriage-line is on the front comb, and has moved from the left to the right 

The front half of the warp is in its tsual position, and the back half has shifted from the left to 
the right. 

The fifth movement is accomplished. 

The sixth movement begins. 

The front carriage-line goes up to the back comb. 

The front point-bar is lowering, and six-twelfths or one-half of rotation of the shafts t ensues. Both 
carriage-lines are on the back comb. The interchange or traversing of the carriages is accomplished 
The carriages have advanced to the right by one station. 
Th.i front half of the warp is in its usual position. 
The back half of the warp has shifted from the right to the left. 


The front point-bar has lowered. It is now exactly in the same position as the back point-bar was 
in the beginning of the first movement, (see Fig. 289,) and is nearly about to fall off. 

The sixth movement is accomplished, and therewith a row Df meshes completed. 

These six movements constitute the first period of operation ) . 

The next, or second period, comprises almost the same movements, with the exception of the comb- 
shiftings, as will be perceived by the following explanation : — 

The seventh movement begins. 

The front carriage-line goes up to the front comb. 

The front point-bar falls off, and lifts the seized row of meshes. 

The shafts t make the seventh twelfth of their rotation. 

The front carriage-line is on the front comb, and the back one on the back comb. 

The front half of the warp has shifted from the right to the left ; the back half is in its usual 

The front point-bar is lifted almost entirely. 

The seventh movement is accomplished. 

The eighth movement begins. 

The back carriage-line comes uj> to the front comb. 

The front point-bar is lifted. 

The shafts t make the eighth twelfth of their rotation. 

Both carriages are on the front comb. 

The front half of the warp having sltifted from the left to the right, assumes iis usual position. 

The back half of the warp retains its usual position. 

Both point-bars are at rest. 

The eighth movement is accomplished. 

The ninth movement begins. 

The back carriage-line goes up to the back comb. 

The back point-bar begins to leave the meshes, and nine-twelfths of rotation of the shafts t ar« 

The back carriage-line is on the back comb, and the front line on the front comb. 

The front half of the warp is in its usual position. 

The back half of the warp shifts from the left to the right. 

The back point-bar has nearly left the meshes. 

The ninth movement is accomplished. 

The tenth movement begins. 

The front carriage-line goes up to the back comb. 

The back point-bar is entirely taken out. 

The tenth twelfth of rotation of the shafts t ensues. 

Both can-iage-lines are on the back comb. 

The front half of the warp shifts from the right to the left, and the back half shifts from the left tc 
Ihe right. 

The back point-bar is about to lower. 

The tenth movement is accomplished. 

The eleventh movement begins. 

The front carriage-line returns to the front comb. 

The back point-bar lowers, and the eleventh twelfth of rotation of the shafts t ensues. 

The front carriage-line is on the front comb, and the back line on the back comb. 

The front half of the warp shifts from the left to the right, and the back half retains its usual 

The back point-bar is near its deepest standing. 

The eleventh movement is accomplished. 

The twelfth movement begins. 

The back carriage-line goes up to the front comb. 

The back point-bar attains its deepest standing. The last twelfth or a total rotation of the shafts ( 
is accomplished. 

Both carriage-lines are on the front comb. 

The front half of the warp is in its usual position, and the back half shifts from the left to the right. 

The back point-bar is in its deepest standing, and about to fall off. 

The twelfth movement is accomplished. A fresh row of meshes is completed, and is forthwith taken 
up by the back point-bar. 

A\ ith the twelfth movement the second period of operations is accomplished, and all is in the posi 
tion of Fig. 2S9. Hereupon the same circulation of movements and functions of the different parts 
begins, and so on. 

The following table will serve to render the just-described periods of movements still more con- 
spicuous. The superscriptions of the columns will prove to be sufficient to explain the signification ol 
the letters ; and it may only be remarked, that A signifies the front carriage-line, and B the back car- 
riage-line. Each column contains tw,o lines, filled either with points or letters, thus indicating the mutual 
position of the concerning threads and carriages after every lateral movement. The asterisks (*) ill 
the column superscribed " Front comb," serve tc direct the attention on the shifting of the comb. 



Taele of the Periods of Movements 
First Period of Movements 


'Front half 
Front comb. 1 of the 

Back halt 
of the 

Back comb. 

Movement of the point-bar. 

End of the 1 2th or beginning 

A B 

. A 

* *A 
*A *B 

* *A 









B ! 
A B 
B . 

B . 

A B 

The back point-bar is about to 
fall off. 

The back point-bar has taken up 
the row of meshes. 

Both point-bars at rest. 

^"he front point-bar is lifted oi i 
of the meshes. 

The front point-bar is about to 

The front point-bar is lowering 

The front point-bar has lowered 
deepest and is about to fall off. 

End of the 1st or beginning 
oi the 2d 

End of the 2d or beginning 
of the 3d 

End of the 3d or beginning 
of the 4th 

End of the 4th or beginning 
of the 5th 

End of the 5th or beginning 
of the 6th 

End of the 6th or beginning 

Second Period of Movements. 

End of the 7 th or beginning 
of the 8th 

. A 
A B 

'. A 

. A 
A B 








B '. 

B '. 
A B 
B ! 

The front point-bar lias lifted the 
row of meshes. 

Both point-bars at rest. 

The back point-bar is lifted out 
of the meshes. 

The back point-bar is about to 

The back point-bar lowers 

The back point-bar is about to 
fall off. 1 

End of the 8th or beginning 
of the 9th 

End of the 9th or beginning 
of the 10th 

End of the 10th or beginning 
of the 11th 

End of the 1 1th or beginning 
of the 12th 

End of the 1 2th or beginning 


A comparison of this detailed statement, with the 'illustration given in Fig. 360, will afford a still 
clearer view of the intertwisting and crossing of the warp and weft or carriage-threads. 

In Fig. 360 the warp-threads are marked with f. They proceed downwards in serpentine lines, and 
receive their contorsion from the tension of the weft-threads twisted obliquely round them alternately 
to the right and the left hand. Before tins union, and beneath the point-bars, the warp-threads are 
tentered vertically. So that the front half of the warp may be better distinguished from the back half, 
the thread? of the former are hatched. 

The front carriage-threads are marked with I; and the back threads with £,. The figure shows the 
texture on a very large scale. The web consists of nine warp and nine weft threads. Five threads 
belong to the back half of the warp, and four threads to the front half. 

Each (horizontally directed) row of meshes contains four holes or meshes. 

The hatched circles within the meshes represent the points of the two point-bars, and are marked 
with M and N. 

Description of an eight-quarters stripe machine. — Machines of this kind furnish bobbinet stripes or 
quillings, forming one broad piece during the fabrication, but winch afterwards are separated from 
each other. 

As these quillings or edgings, for the sake of beauty and solidity, must be, as it were, without a seam, 
this manufacturing requires a particular contrivance in the bobbinet machines. 

The above-described double-locker machine may easily be arranged for manufacturing quillings ; and 
ihe most practical and suitable contrivances for this purpose are those invented by Mr. Croft. 

In Fig. 369 are represented two stripes of equal breadth, and united in such manner as they appeal 
in the whole piece on the lace-beam. The borders or selvages are hatched and marked with / 3 and f. 


The connecting thread, running in zigzag from one mesh to the other, is marked -with k 3 , and the othei 
warp and carriage threads respectively with /and kk t . 

Each stripe being a plain narrow lace in itself, and the carriage-threads proceeding in their slanting 
directions, separately in the one and in the other, of course a contrivance is required in order that the 
carriages may turn back at the two inner selvages as well as at the two outer ones. This and all 
other required arrangements are illustrated by Figs. 361 to 394. 

Fif. 37S represents a double-locker stripe machine in transverse section, in which latter Figs. 3S5, 3S6, 
387, 388, and 389, are also given. The most essential parte of the machine are to be seen in Fig. 378. 

Be^inninn- from below, there will be perceived two warp-beams, G and G 3 . Round the larger one is 
wound the warp for the plain texture, and round the other are twisted the commonly somewhat stronger 
selvages f 3 and f 4 . In case the latter should be of equal thickness as the other warp-threads, one 
beam would be sufficient 

The warp-threads are to be drawn through the kind of reed F, and thence through the series of guides 
c and d, winch are fastened to the guide-bars a and 6. 

The selvage-threads are only laid over the wooden framing-staves of the reed F, (see Fig. 37S,) and 
then (on account of then' peculiar lateral movement) drawn through particular iron or brass ears, (one of 
which is represented by Figs. 391 and 392,) called selvage-guides, which are fastened to the guide-bars 
a 3 and 6 4 . The selvage guide-bars are provided with similar sockets, supports, adjusting screws, levers, 
and springs, as a and b. t 

The warp is not divided into two equal parts as in the machine described above, but is drawn through 
the front and back guides c and d unequally divided, and this in such a manner, that in the front warp- 
half one, and in back half two, warp-threads are omitted at every border of the stripe. The corre- 
sponding guides, in the series of guides, are broken off as superfluous. 

The selvage-threads, on the other hand, are equally divided, drawn through the series of guides c, and 
</ 3 ,yet those marked with f 3 (see Fig. 369) exclusively through the front, and those marked with/, 
through the back series. 

Between the combs L and Li all warp and selvage threads are drawn up in two rows, and led to the 
points n of the point-bars M and N, beneath which the texture is formed, after which it proceeds to the 

The comb and the lockers, and locker-bars p and q, are set up in the usual manner. 

The carriages are likewise put in with two lines, odd carriage, etc., as has been described above. 
Yet in the back line, right opposite to the selvage-threads, there are also the turn-again and whipping 
carriages, briefly called whipper-carriarjes, with the thick and strong connecting threads k 3 , (see Fig. 
309.) The whipper-carriages make upon the whole the same movements as the other carriages, with 
the only difference that they do not shift their places, but are running to and fro in the same bolts. 
During the shifting, they remain in the back comb, while the other carriages change their places in 
each stripe-section. 

Before their peculiar movement, (illustrated by the figures from 37S to 382.) during the shifting, can 
oe explained, some parts and contrivances connected with it must be viewed. 

Close beneath the locker-bars p are parallel with them the so-called picker-bars, to which the pickers 
p 3 are fastened by screws. The picker-bars have exactly such sockets and supports as the locker-bars 
At the one end is fixed a short arm c„ moved by the drawer-bar e; by which the picker-bar, with the 
pickers, can be put in a slight angular movement. 

The pickers, made of stiff hammered iron or brass, Figs. 392 and 393, are performing here the func 
tions of the locker blades in the above-described machine, as they, like them, seize the heels or catches 
of the carriages and push the latter onward, or respectively set them in their places. They, more- 
over, serve to regulate the movements of the whipper-carriages, and are to be advanced as far as 
possible towards the midst, yet in such manner that they may not impede the series of guides in their 
lateral movements. 

To retain the whipper-carriages on the back bolt-bar, the back pusher-bar E, must be placed by a 
particular contrivance, wluch is illustrated b\ r Figs. 378 and 3S1, and especially by Figs. 3S5 and 389. 

The pusher-bar E x , made of strong iron or spring steel plates, is at its long outsides strengthened by 
a rib of wrought-iron and provided with a pivot, by means of which tlie bar is placed in the sockets of 
the cradle-pieces Ii in Figs. 284, 285, 286, etc. The bar has narrow but deep notches, intended to receive 
the whipper-carriages while the other carriages are shifting their places ; but as soon as tins shifting is 
accomplished, the whipper-carriages are let out. and the notches are closed by the covers d, , which are 
fixed to the guide-bar jr 3 , and represented in Figs. 3S8 and 389. The covers are made of thin iron 
plate. The guide-bar g 3 is, by means of iron pieces e 3 , fixed to the above-mentioned rib in such manner 
that it is easily to be moved sidewise, and keeps the covers close upon the notches. The bar is con- 
stantly attracted or drawn by a small but sufficiently strong spiral spring, fixed with its end to the 
pusher-bar E,. The iron pieces e 3 , and the slits of the guide-bar p s , are squared thus, that the covers 
are exactly upon the notches as long as the spring is acting. Fig. 385 represents this movement, 

The uncovering of the notches is effected by a lateral movement of the guide-bar g 3 to the right, and 
this movement is brought on by the action of a lever on the pivot or tenon a t at the bar. 

Figs. 390 (giving a side view) and 391 (horizontal section close above the comb) serve to illustrate 
this movement, K is the front bolt, which, in the moment of tlie shifting, moves from the right to the 
left with the comb L. At its lower edge is applied the trigger h 3 which grasps the short one of the 
two arms of the lever F 3 . The turning takes place on the pivot « 3 fixed at a suitable place in the frame. 
The long lever-arm, bent exactly in conformity with the curve of the comb, and placed in such manner 
that it is tight beneath the bar E„ lies close to' the left side of the tenon a,. 

_ Thus as soon as the bolt-bar K is moving to the left, the long arm of the lever F 3 , moving to the 
right, presses against the tenon a,, overcomes the power of the spiral spring, pushes the guide-bar g 3 to 
the right, and opens the notches of the pusher-bar. 



The notches must be kept open until the shifting is accomplished. But the bolt-bar turning again 
from the left to the right, after the first quarter of the shifting movement, and, consequently, the long 
arm of the lever F 3 making the inverse movement, the covers would close the notches again and bring 
about confusion, if there had not been made a contrivance for preventing it. The chief instrument of 
this contrivance is the parry ing-ledge h„ screwed on the back bolt-bar. Its position relative to the 
lever F 3 and the tenon a, is shown by the Figs. 390 and 301. The tenon a., leans against the parrying- 
ledge as soon as it is pressed by the lever F 3 , and does not give way until the shifting is accomplished. 
The positions of the tenon a,, marked with dotted points in Figs. 390 and 391, will sufficiently illustrate 
this statement. 

We shall now take a view of the peculiar movements of the whipper-carriages in the moment of the 

Fig. 373 represents the concurring parts in the movement when the shifting of the front comb begins. 
Both carriage-lines are on the back comb. 

In the next movement the comb makes its lateral movement ; the lever F 3 acts upon a t , and the 
notches of the pusher-bar E, are opened. Simultaneously the baok pickers are, by the angular move- 
ment of the picker-bars, moved upwards. They now seize the shifted carriages at then heels or catches 
and push them onward, see Fig. 379, while the other carriages remain at then- places, and the whipper- 
camages (marked with k 3 ) pass into the notches of the pusher-bar E^ 

Now the movement of the pusher-bar and locker begins ; E, pushing onward those carriages, which 
are not retained by the pickers, and the back locker lowering. As soon as the outer locker-blade is 
within the back heels of the retained carriages, the pickers move downwards, the just-mentioned 
carnages are seized by the outer blade of the back locker, and the carriage-movement ensues in the 
usual manner. The front locker draws the carriages, pushed to it by the pusher-bar E„ up to the front 
comb, where, opposite to each whipper carriage, one common carriage is lacking, (which may appear a 
matter of course by the above given statement,) and is instead of this in the back line of it. The back 
carriage-line on the back comb is complete, and has behind itself the line of the whipper-carriages which 
had been retained in the notches of the pusher-bar E,. (See Fig. 3S0.) 

The comb moves back ; the carriage-movement ensues ; the back pusher-bar causes all carriages, 
without any exception, to move onward ; the back locker falls off and the front locker seizes the 
carriages presented to it and draws them up to the front comb. But just before the front locker seizes 
the heels of the carnages, the back pickers move upwards again, and consequently retain the whipper- 
carriages on the back comb. Meanwhile the other carriages have been drawn up to the front comb, 
where now two lines are, of wliich the inner one is complete, wliile in the outer one as many carriages 
are lacking as there are whipper-carriages on the opposite side. The position of the concurring parts in 
this movement is represented by Fig. 381. 

The back pickers are thus, in this period of movements, performing the function of the back locker, 
which (as is shown by Fig. 3S1) has completely turned round, and cannot, for this reason, retain the 

As soon as now the front comb has moved again from the right to the left, the front pickers spring up, 
and, seizing the (not in pairs) standing carriages on the front comb at then- heels, press them upwards 
until their back heels or catches are beyond the outer blade of the front locker. (See Fig. 3S2.) The 
back pickers remain in their position represented by Fig. 381. Then the usual carriage-movement 
begins, and before the front comb moves from the left to the right, the front as well as the back pickery 
fall off. The comb-shifting ensues, and now both carriage-lines on the front and on the back comb are 
complete. The interchange or traversing of the carriages throughout the whole width of each texture- 
stripe has occurred, and the movement of the carnages of the complete lines continues in the usual 
manner until the shifting takes place anew. 

This shifting, i. e., the interchange or traversing of the carriages in the texture-stripes, is indeed not 
easily to he understood ; however, the following statement will prove adapted to render the matter 
pretty clear. 

The common carriages are marked with a, 6, c, d, e, f, ff, h, k, and the whipper-carriages with A 3 ; 
then number is in conformity to the pattern hi Fig. 369. The position of the carriages and combs is, 
according to Fig. 37S, the following : 

First Position 

r . a 
. k 

b c 
k ff 

d h 

f ° 


b c 

>' ff 


h ■ 


y back comb. 

after the first shifting of 
the front comb. 


• (. front comb. 

The big points represent the concurring places for the carriages. As soon as the carriages are i* 
the front comb, their position is the following: 

. ... h .... h . ) 

. . . , > back comb. 

a o c a e a o e a e . , . ) 

First Position. 

k h ff f 

I front 



abode abed 

■ back comh. 

After the comb's lateral movement to the light, the carriages stand thus : 

[" . ... h .... fa . 

Second Position, 


k h g f . k h g f 

This position corresponds to Fig. 3S0 ; yet as soon as the back carriage-lines have passed the froDt 
comb, the position is tiie following : 

Second Position. 

abode abode 
. k h g f . k h g f 

The comb mores to the left, and now the carriages stand thus : 

.... fa .... fa 

Third Position. 

- back comb. 

■ front comb. 

• back comb. 

a b c d e a bode 
. • * h ff f • k h g f 

• y front comb. 

Tliis position corresponds to Fig. 381. The carriages move up to the back comb, and their position u 
now the following : 

■ • ■ I back comb 

b e d e fa b c a e fa . . . ) 

Third Position. 

a k h g fa k h g f 

■ front comb. 

The comb moves back, and the shifting of the carriages is now accomplished ; for the position ie 

Fourth Position. 

b c d e fa b c d e fe 

a k h g f a k h g f 
&c, <tc, Ac. 

■ back comb. 

• front comb. 

This statement shows at the same time clearly, that all carriages, as for instance, e in the first posi- 
tion, or as after the shifting/ in the fourth position, which are with the whipper-carriages in one and 
the same bolt, are doing the business of whipper-carriages. 

At the ends of the carriage-lines no whipper-carriages nor pickers are required, because the hold- 
fast contrivance, applied here, together with the notches of the lockers, supply the action of the 

The above explained interchange or traversing of the carriages is rendered necessary by the men- 
tioned order of the warp-threads, and that the stripes of the texture may be provided with seams. 

In manufacturing plain broad pieces, the front half of the warp containing one thread less than the 
back half, there must be in a pattern like that of Fig. 3G9, four front and five back warp-threads in 
each stripe. Further, the borders or selvages of plain broad pieces being made of the end 
threads of the back warp-threads, consequently the seam-threads of the stripes must likewise be 
contained in the back half of the warp. But as here, on account of the connecting thread, (running in 
zigzag.) the left seam-thread of a stripe must alternately pass over two bolts, these threads are to b« 
drawn through particular guides adapted for tins movement, 


The lateral movements of the guide-bars are in the usual manner prepared by ratehet- wheels, levers 
and angular pieces, or swing-bars. But for effecting the just-mentioned movement for the particular 
guiding of the seam-threads, the stripe-machine must be provided with two ratchet-wheels more, 
which are fastened at the axis t, to the right of the machine. Besides these, there are required two 
other ratchet-wheels for the movement of the pickers, which are fastened at the same axis within the 
dented wheels t x and t v (See Fig. 2S6.) Sometimes the last-named wheels are arranged for this pur- 
pose in the manner illustrated by s< in Fig. 390. 

The figures from 370 to 377 represent all ratchet-wheels of the double-locker stripe-machine. The 
directions of the arrows indicate those of the movements. The various acting points in the twelve 
different movements of the concurring parts are marked with ciphers. Equal marked points are simul- 
taneously acting. Point 1 corresponds to the acting point indicated by Fig. 378. 

Fig. 370 represents the right ratchet-wheel for the lateral movement of the comb; Fig. 371 the left 
one of this description; Fig. 372 the front ratchet-wheel for the warp-threads, and Fig. 37-4 the back 
ratchet-wheel for the same purpose. (These four wheels, already known by the description and illus- 
trations of the broad plain bobbinet machine, are delineated here once more, in order to facilitate the 
view jf the whole.) Fig. 373 represents the front ratchet-wheel for the seam-threads; Fig. 375 the 
back ratchet-wheel for the same purpose ; Fig. 376 the back ratchet-wheel for the pickers, and Fig. 377 
the front one of this descriptioa 

Following in the order of numbers the indentments of the ratchet-wheels, it becomes apparent that 
during the twelve different movements of the two principal movement-periods, (in which two rows of 
meshes are completed,) the shiftings of the warp-tlu-eads occur simultaneously, and in a successive 
order. Still more perspicuous the simultaneous operations of the ratchet-wheels will appear by sup- 
posing their peripheries to be stretched out into a straight line, as has been done in the following sketch. 

By the lateral shiftings of the warp-threads, and by the interchange or traversing of the carriages, 
the formation of the web is effected ; and all the intertwistings and decussations of the threads follow 
each other in the same order, as has been sufficiently explained above. The connection of the seam- 
threads with the connecting thread A- 3 , (Fig. 369,) is not brought on by perhaps a lateral movement of 
the latter, but only by the lateral movements of the seam-tlireads. Thus the intertwisting of k a and/ 
(in the midst of the figure) is effected by a single shifting of the latter towards the former thread, (ex" 
plained by Fig. 373,) while the intertwisting of the left seam-thread/, is effected by its double-shifting 
(See Fig. 375.) 

The positions of the warp-threads towards each other and towards the carriages in the two principal 
movement-periods, are exposed in the folio whig statement. In this a, b, c, d, e, f, g, h, k signify the 
common carriages, ki the whipper-carriages ; the asterisks (s(:) signify the back seam-threads ; the 
simple crosses (4-) the front seam-tlireads ; the large points (.) the common front and back warp- 
threads ; and the vertical dashes ( | ) the void places for the carriages. The statement corresponds to 
the texture of Fig. 369. 

First Movement. Acting point 12. 

back comb. 

d ki a b c d A'3 ) 

. I I I I I I I I I 

S(e .... jf: .... Jf. back seam-threads. 

.... .... back warp-threads. 

. . . . . . . . front warp-threads. 

-|- . . . . -[- front seam-threads. 

k h 3 f t h' h g f e I ... .front comb. 

I I I I I I I I I I J 

Second Movement. Acting point 1. (Position as in Fig. 37S.) 

a b c d ki a b c d kz ) 

. , . , . , -... .back comb, 

khgfekigje ) 

jf: . . . . 3$e . . . . s^c back seam-threads, 

r ■ . . .warp-threads, 
4- .... -f- front seam -thieads, 

I . | j ■] | | i j [...„ 

Third Movement. Acting pr/'.nt 2. 

i ; i i *» i i i i h I , . . 

1 , , . , '- . . . .back comb, 

a oc de abode ) 

if, . . . •)/: . . . . jjc back seam-tlireads. 

'- . . . warp-threads, 

-f- . . . . + front seam-threads, 

q f \ k h g f | 

-... .iront comb, 
I I I I I I I » 



Fourth Mov 



ing point 3 













. .back comb, 



. .-warp-threads, 












. .front comb, 




ng pc 

int 4. 















. .back comb, 


. .warp-threads, 
















. .front comb, ., 

Sixth Movement. Acting point 5. 
A r/ / a k h g f \ 

I I I 

I I I I I I 

I I I I I I 

. .back comb. 

. .back seam-threads, 

. .warp-threads. 

. .front seam-threads. 
. .front comb. 

Now the first principal movement-period is finished, and one row of meshes is completed T2s» 
point-bars take up the completed row. 

Seventh Movement. Acting point 6. 

I I I I I I I I I I 

b c d e A'3 b c d e lz 

, . .back comb. 

, . .back seam-threads. 

i i i 

l i i 

f a 
I I 

■ + 
h 9 f 
I I I 

Eighth Movement. Acting point 7. 
I I I I I I I I I 

I I I I I I I I 1 

* ... * 

h b 

f a 

d e 
h g 

Ninth Movement. Acting point 8. 

I I I I I 

b c d e jh 


/ a 
1 1 





. .front comb. 

. .back comb. 

. .back seam-threads. 

. .warp-threads. 

. . front seam-threads. 

. .front comb. 

. .back comb. 

. .back seam-threads. 

. .warp-threads. 

. . front seam-threads. 

. .front comb. 


Tenth Movement. Acting point 9. 
b c d e )<i b c d e ks 
akhgfakhg f 
s(c 3jc .4; back seam-threads. 

, . .back comb. 

y . . . .warp-threads. 
+ . . + front seam-threads. 

.front comb. 

I I I I I I i I I I ) 

1 l I I I I I I I I F 

Eleventh Movement. Acting point 10. k 3 |-.... backcomb. 

■% . . . jfc . . . .^ back seani-threads. 

,- . . . .warp-threads. 

-f- . . + . front seam-threads. 


I I I I I I I I I 

Twelfth Movement. Acting point 11. 

... .front comb. 



1 1 
| | 

1 1 
| | 



1 1 
1 1 

. . . .back comb. 


■ + 




. . .warp-threads. 




e h 
9 f 

6 c 
a k 


e k 3 
9 f 


. . .back comb. 

Now the second principal movement-period has finished, a fresh row of meshes is completed, and forth 
n ith taken up by the back point-bar, and in this manner the cycle of movements is continuing. 

The points of the point-bars take up the completed meshes in the usual manner, only two points in 
die midst are somewhat bent sidewise to give room for the connecting thread. (See Fig. 394.) 

The breadth of the stripes is commonly fixed in conformity with numbers wliich coincide with the 
number of meshes running diagonally. Thus, for instance, the stripes in Fig. 369 would be marked with 
No. 8. 

Figured bobbinet (or design bobbinet) is manufactured in three different ways : — 

The common plain bobbinet is interwoven with embroidering or twisting threads. This inter- 
weaving can be done at single spots, as well as in continued lines. The first manner produces points 
or spots regulated by groups and figures of various descriptions ; and the second manner produces orna- 
mental stripes either in serpentine lines, or in zigzag, or otherwise arranged. The ornamental or 
embroidering threads consist usuall " -?f thick or colored yarn, in order that the pattern may have a 
better relief. 

Machines for manufacturing bobbinet, of this description, are : Sncath's improved single-locker ma- 
chine ; Heathcoate's patent machine ; Summer's lever machine ; Sewell's roller macliine ; Draper's ma- 
chine, and While's improved machine. — -The arrangements of these machines are very different, and it 
would lead us too far, to give any description whatever of them here. Heathcoate's machine is connected 
with a so-called tatting machine, by which the interweaving of ornamental threads is performed. 

The simple intertwisting of threads in the plain bobbinet is altered in such manner, that at certain 
points of the web, larger holes or meshes are made, surrounded by common smaller ones. Some pat- 
terns of this description are called greciam net, the honey-comb open work, and the roseau full. 

The manufacturing of these webs requires, of course, more or less complicated arrangements in the 
machinery. Their chief peculiarity is, that the warp is to be divided m more than two parts, which have 
their lateral movements independent of each other. Frequently the movement of the carriages is in 
certain movement-periods somewhat altered too, similar to the case of the stripe-machine, which 
may indeed be considered as producing figui ed or design bobbinet, if the zigzag connection be regarded 
as a figure. 

The arrangements of the first and second systems are combined, by which we obtain patterns with 
larger, and meshes with ornamental threads. Draper's machine is partly adapted to them. Upon the 
whole, the machinery is very complicated ; and for tliis reason, almost everywhere the lever and single- 
locker systems are applied, because machines of this description can be more conveniently arranged and 
altered than double-locker machines. 

BOILERS, for the generation of steam for engines, may be divided into three great classes. The 
and or rtatiorary boiler, the locomotive boiler, and the mariue boiler. In the first the combustion is 



the least active, in the second excited hy means of the exhaust or artificial draft. In the first the pnn. 
ciples of combustion and proportion of parts are pretty accurately determined, but the circumstance! 
under which the marine boiler is placed and the conditions it is required to fulfil are so different that as 
yet no one form, dimensions, or proportions car. be said to he the standard. 

Stationary Boilers. The capacity of steam-boilers should at least equal one cubic yard, or 27 cubic feet, 
for each horse-power, being a minimum space of 135 cubic feet for steam, and a maximum space of 13-5 
cubic feet for water. In cylindrical boilers, plain, without any inside flue, and set upon the oven plan— that 
is the (lame and smoke passing direct from the bottom of the boiler to the chimney without any retain 

QUe j^ maximum length in feet is 6 times the square root of the horse-power, or, if with a wheel 

draucht 4 times the square root of the horse-power. In cylindrical boilers with inside flue or flues passing 
IhrouWthem, and with split draught, 3| times. If Sued, and with inside uptake set with split draught, 
the length in feet should he from 3 to 3| times the square root of the horse-power; or, if with wheel 
draught, 3 times. . 

The ash-pit and entrance to it should be as large and free as possible. The area for entrance of air 
to ash-pit never less than \ the area of grate ; 2 feet 6 inches is sufficiently deep for ash-pit. 

The fire-bars inclining downwards 1 inch per foot, and cast as thin as possible consistent with neces- 
sary strength, not more than | inch thick, and with § or ■£ inch spaces between. 
The furnace should have 3 cubic feet of space above each superficial foot of fire-bar surface. 
Flues.— To determine the area of the flue and chimney, it must be considered that 150-35 cubic feet 
of air are required for the combustion of 1 lb. of coal. Of this air 44-64 feet combine with the gases 
evolved from the coal, and 10571 feet with the solid portion of the coal. The combination of the air 
and gases increases their volume l-10th. The 44-61 feet thus become 49 104 feet. The sum of 10535 
with the carbon remains the same. The total product of the combustion (without considering the in 
crease of volume resulting from raising the temperature) of 1 lb. of coal, is therefore 105-71 -j- 49104 
= 154-814 cubic feet. Assuming the temperature of the furnace at 1000° Fahr., at which aeriform 
bodies are expanded to about three times their original bulk, the product will be 154814 X 3 = 464*442 
feet. Adopting- the result of Dr. Ure's experiments, viz., that the products of combustion pass off at a 
velocity of 36 feet per second, the area to allow this quantity to pass off in an hour will be -516 square 
inch. In a furnace in which 13 lbs. are burnt per hour on each square foot of grate, which is, according 
to Mr. Parkes, the average consumption throughout England, the minimum area over the bridge, or 
of the flue immediately behind the furnace, would be 516 X 13 = 6-709 square inches. In practice, 
□owever, as a large surplus of air is always admitted, and the exactness supposed in this calculation 
cannot be secured, it is found advantageous to make the area 2 square inches instead of -516. This 
gives 26 square inches of area over the bridge to every foot of grate where 13 lbs. of coal are consumed 
par hour to every foot of grate. As the temperature and bulk become gradually reduced in proportion 
\o the distance from the fire, the area of the flue towards the chimney may be narrowed ; but thia 
efcir-jild be done without awkward bends or sharp angles. 

Proportion of heating or flue surface to sue of yrate. — In boilers burning 13 lbs. per foot per hour, 
18 superficial feet of heating surface to each foot of grate is a good proportion. This proportion omits 
the bottom surface of flat flues, and from J to i the surface in circular flues, as being inoperative. 

Chimneys. — The area of the chimney should be J that of the opening over the bridge, viz., 1i inch 
per lb. of coal consumed, or 19|- inches for each foot of fire surface burning 13 lbs. per hour. But the 
whole diminution of flue should be made gradually, and not by any sudden contraction. A common 
rule is, that the minimum area of chimneys 24 to 30 yards high, is 4000 square inches for each 20 

Furnaces and Boilers. — From a careful examination of some of the best constructed boilers and tunia- 
ces in Manchester, the ratio of grate-bar to absorbing surface was found to he 1 : 11*1, which, taken 
from fifteen boilers of the best construction, and worked with considerable skill, gives a fair average of 
the proportions of the furnace and the flue surface of each. On comparing the above with the boilers 
at work in Cornwall, it will he found that their relative proportions are as 1 to 25 ; and while G lbs. of 
good coal will evaporate in the Cornish holier about 11J lbs. of water, the utmost that the best 
wagon-shaped boiler has been known to accomplish is S - 7 lbs. of water to the lb. of coal. Hence the 
advantage of a small furnace and large flue surface, united, however, to abundance of boiler space, in 
order to attain a maximum effect by a slow and progressive rate of combustion. 

Taking the amount of flue surface in a boiler exposed to the passing currents of heat as a criterion 
of its economic value, we shall theu have according to computation a summary of comparison as follow* ■ 


Description of boiler. 

Cubic con- 
tents in feet. 

Area of heat- 
ed surface in 

Ratio of the area 
of heating sur- 
face to cubic con- 





1 : 3-28 
1 : 3-26 
1 : 206 
1 : 3-50 
1 : 1-65 
1 : 106 
1 : 101 

Common wagon-boiler, without middle flue 

: 6 

1 7 

Cylindrical boiler, with eight 10-inch iron tubes . 


Armstrong on Sicnm-IVil.T; 



On the various forms of stationary boilers, Fig. 395, repre- 
sents the vagon boiler, sometimes called the caravan or oblong 
boiler. This boiler succeeded the haystack boiler, but it is not 
adapted to resist the pressure of high steam ; but up to 5 i'eet 
diameter, if provided with one or two or three longitudinal 
stays, of li inch square from end to end. and cross stays at 
every two feet in the length, it may he safely worked tip to 10 
lbs. per square inch, and the evaporative results are economi- 
cal. Their length is commonly from 16 to 24 feet. They are 
seldom used in this country. 

Plain cylindrical boilers set in brick work, are in very com- 
mon use for stationary engines, and especially at such places 
as it is inconvenient to get workmen to make repairs. They 
are usually from 30 to 40 inches in diameter, and from 30 to 
40 feet long. The grate is placed at one end, being of about 
the width of the boiler and from 3 to 5 feet long. The chim- 
ney is at the opposite end. At the end of the grate is placed 
a bridge, as it is termed, which forms a hack for the grate, and 
being bronght within a few inches of the boiler, brings the 
flame in contact with its under surface. 

Cylindrical boilers are often set in connection with each oth- 
er, side by side. "When set in rows, one above the other, or 
in nesfSj as they are called, the upper row being directly above the 
lower one, as in figs. 396,397, or better over the spaces, (there 
being one less boiler in the upper than in the lower row,) the 
evaporative effects, as instanced below, are excellent. 

These boilers, which have now been in use by the Lowell Manufacturing Company at Lowell for two 
years, were constructed, from directions by Dr. A. A. Hayes, of Boston, by Messrs. Bancroft, Nightin- 
gale & Co., of Providence. One row of four boilers are set perpendicularly above another row of the 
eame number, the fires being under the lower tier. The boilers are plain cylinders, 40 feet long and 33 
inches diameter, having a surface exposed to the fires of 2,000 square feet, and containing about 1,200 
cubic feet of water. The grates are in two heights of 3 feet 2 inches each, with a width of 12 J feet, 
giving a fire surface of about SO square feet. Each grate is 1J inch thick, having between it and the 
next one a space of a quarter of an inch wide, giving the whole of the space for the passage of the air 
to the fires equal to about 10J square feet. The dampers at the back end of the boilers are usually 
kept open about four inches, giving an area of four and one-sixth square feet for the exit of the smoke. 
The upper and lower tiers are connected by thimbles in four places in each boiler between their ends, 
while at the ends are a number of connections, as shown. The thimbles are of cast-iron, having a socket 
turned in its upper part, into which a tube is set, reaching to within eight inches of the top of the upper 
boiler. The connections at the ends are of cast composition metal, and notwithstanding their number no 
leakages have occurred. A steam drum, 11 feet long and 33 inches diameter, is connected with each ol 
the upper boilers, and is placed above them ; from this drum steam is taken to the engines. Accurate 
measurements and accounts have been kept of the amount of coal used, and of the water evaporated 
by it, which show that for the last year together, the average amount of water evaporated to one pound 
of coal consumed was 9.66 lbs. 

The amount of coal consumed under each nest of eight boilers per day is about 2 J tons, and by com- 
paring the weekly averages of effect, it appears that, even with this large amount of boiler compared 
to the fire surface, that the less the amount of coal consumed per day the better the effect. 

For example: the amount of coal consumed under two nests of these boilers during the week ending 
Feb. 18th, 1S48, was 65 tons, which e^ .oorated 8.72 lbs. of water for each pound of coal consumed, and 
during the week ending July 14th, 1S4», 21 tons of coal only were burned, and 10.44 lbs. of water were 
evaporated for each pound of coal consumed. The best result from a week's working was obtained du- 
ring the week ending May 7th, 1849, when 11.62 lbs. of water were evaporated by each pound of coal 

The steam from two nests of these boilers is used at a pressure of 65 lbs. per square inch, by a 
double high-pressure engine of 200-horse power, and a single engine of 40-horse power, both of wliich 
exhaust into pipes under a pressure of five pounds per square inch, from which it is used for dying, dry- 
ing, and heating. 

Somewhat similar to the nest boilers are the eleplmnt and retort boilers. The former consists of two 
■mall cylindrical boilers set beneath a larger one, connected by legs at each end, hence probably the 




name : the upper boiler being the body, and the connections the four legs. The grate is placed be- 
neath one end, and the fire is brought in contact with the whole surface of the smaller boilers, passe« 
to one end, and returns beneath the bottom of the larger boiler ; the legs being sufficiently long to ad- 
mit a division or arch of brick between the upper and lower boilers. These boilers are very popular in 
France and on the Continent, but have been used here in few instances. A good proportion for one of 
these boilers is as follows : — length, 24 feet ; upper boiler 4 feet diameter, ends egg shaped ; the lower 
tubes 2 feet 2 inches diameter, and separated from each other about 3 inches; water legs 18 inches di- 
ameter, and fire grate 5 feet wide by 6 feet long. The ends of the tubes may be made to project be- 
yond through the brick-work, and have cast iron heads ; but the ends of the upper boiler are usually 
in the flue.^ At the " India Mill," in Stockport, England, there is one of these boilers 35 feet long by 
5 feet diameter in the main barrel ; lower tubes, 2 feet 3 inches diameter; water legs, 16 inches diam- 
eter and 2 feet 3 inches high. Two of them are capable of exerting about 500 indicated horse power, 
consuming about 3 lbs. of coal per horse power per hour, and are worked under a pressure of 64 lbs. 
per square inch. 

The Ketort boilers consist of several small boilers or tubes, say from 16 to 20 inches diameter, ar- 
ranged in rows some 2 or 3 inches apart, the spaces being filled in with brick. The steam spaces of 
these tubes are connected by legs to a steam drum above placed crossways of the tubes. The tubes are 
short, and are placed crossways of the grate, and the flame is brought in contact with the under surface 
of the tubes and returned over the top, the one being the water and the other the steam space. In this 
way the steam becomes super-heated, the intention of the boilers being for the generation of very high 
steam, as high as 250 lbs. to the inch. Retort boilers somewhat similar to the above were constructed 
by Dr. Alban on the Continent, of smaller tubes, and worked with much higher pressure. 

Flue Boilers. Flue boilers are of various forms ; the simplest are cylindrical boilers with single or 
double return flues passing through them. In some the fire is made beneath the boiler at one end, the 
flame passing beneath the boiler and returning through flues in the boiler to the front eud, where the 
chimney is placed, or making one return through one flue or set of flues, it is again returned by another 
set to the rear to the chimney. Still in another the boiler is made cylindrical, with the lower half cut 
away a t one end for the reception of the grate, and the flame passes directly through the flues, and re- 
turn s by one side of the boiler and back by the other, or makes but one return, and that beneath the 
boiler, the chimney being placed at the front end. 

Figs. 398, 399, 'These flues may be 
S£)9. either large and few, or more numerous 

and smaller ; the latter class when tubes 
are used are called locomotive boilers, al- 
though used for stationary purposes. The 
advantage of this form is, that the hot- 
test part of the flame is brought in con- 
tact with the top of the water : desirable 
whenever the top of the fire-place and 
flues can be kept covered with water 
Scale.— l-20;h in. = 1 loot, with certainty. The top of the fire-box 
Transverse Section being a flat or concave surface, it is 

therefore weak unless very strongly stayed. 

Scale.— l-20th inch=l foot. 
Longitudinal Section. 

The Cornish Boiler, similar to fig. 398, is a cylindrical boiler, with an internal flue or flues passing 
through the boiler, and thence being returned en one side and back on the other; or making the first 
return at the sides, is brought back beneath the bottom of the boiler. The diameter of the Cornish 
boilers is usually about, one-sixth of their length, a common proportion is from 36 to 40 feet in length, 
and from to 7 feet in diameter. The pressure per square inch is from 15 to 35 lbs. The great econ- 
omy of the Cornish boiler is found in the large proportion of fire in the slow combustion, in the great 
care taken in firing and keeping a register of the duty, and in the protection of the boiler from radiation. 
400. tm F'S S - 4^0i 401, is a 

form of boiler prepar- 
ed and patented bv 
Wm. B. Johnson. The 
furnaces, two in num- 
ber, are placed, one at 
each end of this flue, 
and the gaseous cur- 
rents therefrom tra- 
verse — as shown by 
the arrows — meeting 
and mingling with 

tacli other in the central space between the two bridges. There the gasses are well mixed and ignited, 

prior to the combined current passing off through the outside bottom flues. Figs. 402, and 403, exhibit 

W2- 4* 13 - similar sections of a 

tubular boiler with a 
single furnace. The 
gases here pass from 
the furnace into the 
chamber at the back 
of the bridge, and 
thence through the 
flue tubes into an ene 



smoke-box, in communication with the chimi.ey flue. The smoke-bos has an end door for cleaning, 
and is well surrounded with water. 

Fii-s. 404, 405, 406, 407, represent views of an upright tubular boiler well adapted in some situ- 
ations for stationary purposes. 

ec inn through Ashpit, showing 
slays »r bottom water space. 

Section through Tubes. 

1 foot. No. 1. 
Perpendicular Section 

The Eijg-Shaped Boiler, Figs. 408, 409. This boiler is 
known as the " upright egg-boiler," and is much used in 
Staffordshire, from the circumstance of its being so well 
adapted to being worked by means of the waste heats 
of the puddling iurnaces. It is not easy to conceive a 
form of boiler more suitable for such au arrangement, 
especially where high-pressure steam is required. 

Two of these boilers at Messrs. Thorneycroft's Shrubbery Iron-Works, each about 9 feet diameter 
and IS high, make sufficient steam to work at about 80 horse-power, entirely from the spare heat or 
heated gases and smoke proceeding from four puddling furnaces, (two to each boiler,) which heat had 
previously gone wholly to waste. 

From some estimates of the consumption of fuel by Messrs. Thorneycroft's engine, (a 4S inch cylin- 
der,) when worked by boilers of the ordinary horizontal construction, there is every reason to believe 
that a considerable gain may be made by adopting this construction of boiler generally, for ordinary 
stationary or manufacturing purposes. Its great economy arises, in a great measure, from the vertical 
inside flue, the whole of the interior surface of which may be considered as effective in generating 
6team, in place of the upper half only of the common horizontal flue. And this beneficial efficiency, 
„.„ it is probable, may be further increased, if the 

lower end of the inside flue was made a few 
inches wider than the top, thus giving a better 
position for the generating surface. 

a, b, c, d, in the plan show the places, 
with respect to the inside flues, at which the 
hot air or flame is discharged from the pud- 
dling furnaces. 

Fig. 410, represents a longitudinal section, and fig. 411, a front view of a single return drop flue, 
rach as is used to drive the pumping engines at the Brooklyn Dry Dock. The boiler itself is 84 inches 
in diameter ; a regular fire-bos is made at one end, and the smoke and flame pass through a number 
of small fines at the upper part of the bos, and are returned through larger and less numerous ones at 
the bottom of the boiler nearly to the fire-bos again, where they are taken off laterally into the chimney. 
All the flues, and hoses at the end of the flues, are included within the shell of the boiler ; the boiler 
is covered with brick-work and ashes. Boilers of this form give very escellent evaporative returns, and 
are used much in this country both for statiouar} r and marine purposes. 





1 ;; ; -- 



jgZQr. 1 | ^1 



The Locomotive Boiler (Fig. 412) represents a section of a common locomotive boiler, anil fig. 413 
is an end view of one-half of "the smoke end. The proportions of locomotives are considerably varied 
by different makers, but the general arrangement is always preserved. The diameter of the tubes va- 
ries from l± to 3 inches, and the length of the tubes from 7 to 14 feet. We give the investigations of 
the Principles of the Locomotive Boiler, by Daniel K. Clark, of Edinburgh, a paper read before the 
London Ins., C. E., as the most extended and reliable of any yet published; but it must be observed 
that the engines experimented on were coke engines, a fuel little used in this country ; the application 
of the same .-principles might not obtain entirely in wood and coal engines. For a comparison of th 
engines of the different varieties, we subsequently extract from the valuable Report of G. W. Whistler 
Jr., to the Reading R. R., Pa. 




I ■' 1, ' 

r :i| i! 



The evaporation of 12 lbs. of water per pound of pure coke was found, by careful laboratory experi- 
ments, to be the maximum of evaporative performance ; in the best ordinary practice an actual evap- 
oration of 9 lbs. of water per pound of coke, or 75 per cent, of the possible maximum, was readily 
obtained, the balance being lost by leakage of air and by waste ; and it was adopted by the author as 
the ordinary standard of practical economical evaporation. 

A minute analysis was made of the results of numerous authenticated experiments on the evapo- 
rative power of locomotive boilers, of very various proportions, on the engines of the Caledonian, Ed- 
inburgh, and Glasgow, and Glasgow and Southwestern Railways. It was concluded, that the economi- 
cal evaporative power of boilers was materially affected by the area of the fire-grate, and by its ratio 
to the whole heating surface ; that an enlargement of the grate had the effect of reducing the economi- 
cal evaporative power, not necessarily affecting the quality of combustion in any way, but governing 
the absorbing power of the boiler, as the lower rate of combustion per foot of grate due to a larger 
area, in burning the same total quantity of fuel per hour, was accompauied by a reduced intensity of 
combustion, and by a less rapid transmission of heat to the water, in consequence of which, a greater 
quantity of unabsorbed heat must escape by the chimney. An increase of heating surface agaiu, re- 
duced the waste of heat, promoted economy of fuel, and added greatly to the economical evaporative 
power. Iu short, the question resolved itself into the mutual adjustment of three elements — the neces- 


sary rate of evaporation, the great area, and the heating surface, consistent with the economical gene- 
ration of steam at the assumed practical standard of 9 lbs of water per pound of good coke. An inves- 
tigation of the cases of economical evaporation, in the " Table of Experiments," conducted the author 
to the following important equation, expressing the relation of the three elements of boiler-power ; in 
which c was the maximum economical evaporation, in feet of water per foot of grate per hour ; h was 
the total heatinc surface in square feet, measured iuside ; and g was the grate-area in square feet . 

c =z -00222— 
From this it followed : 1st, that the economical evaporative power decreased directly as the area of 
grate was increased, even while the heatin J surface remained the same ; 2d, that it increased direct- 
ly as the square of the heating surface, when the grate remained the same ; 3d, that the necessary 
heating surface increased only as the square root of the economical evaporative power ; 4th, that the 
heating surface mnat be increased as the square root of the grate-area, for a given evaporative power. 
It was contended thence, that the heating surface would be economically weakened by an extension of 
the grate, and would be strengthened by its reduction ; and that whereas large, grates were commonly 
thought to be an unmixed good, and being generally recommended were usually adopted, still they 
might be made too large — not that their extension affected the quality of combustion, but that the eco- 
nomical evaporative power might be reduced. Concentrated and rapid combustion was alike the true prac- 
tice for the largest and the smallest boilers ; and, in locomotives where lightness, compactness, and effi- 
ciency were primary objects, the boilers should be designed for the highest average rates of evapora- 
tion per foot of grate that might be followed in good practice, consistently with the highest average 
rate at which coke could be properly consumed ; as, in this manner, the smallest grate and the small- 
est amount of heating surface consistent with good practice might be employed. It was stated that 
150 lb. to 160 lb. of good sound coke could be consumed per foot of grate per hour ; And, allowing for 
inferior fuel, an average maximum of 112 lb. per foot of grate was recommended as a general datum. 
This determined the average maximum of economical evaporation to be 1 6 feet of water per foot of grate 
per hour, allowing 9 lb. of water per pound of coke ; for which 85 feet of heating surface per foot of 
grate should be provided. It was accordingly recommended that a heating surface at least S5 times the 
grate-area should be adopted in practice. 

Such experiments as " midfeathers," &c, which were resorted to for specially increasing the fire-box 
surface, were condemned, as they were considered to be no better than tubes, whilst practically they 
were inconvenient and costly; as, among other reasons, plates of ^ inch or \ inch in thickness were 
employed to do the work of the tubes, which were less thau J inch in thickness. 

A practical rule followed by some engineers, and stated to he founded on extensive experience, was 
to allow 5 feet of heating surface for 1 foot of water evaporated per hour, and 100 feet of evaporating 
er.rfaee per square foot of grate. Those results were found to agree with the maximum rates recom- 
mended in the paper. It was also argued that the intensity of combustion materially affected the 
amount of heating surface necessary for economical evaporation, being less as the intensity was greater. 
It was contended, on the other hand, that the formula as stated in the paper would not apply to all 

It was further argued that, from various causes, no formula could be framed to be of service unless all 
the circumstances in each case were properly taken into account. 

As an example of the objections to long tubes, the results were given of the work done by a luggage 
engine on the London and Northwestern Railway, before and after alteration. That engine originally 
had tubes 11: feet long, with a total surface of upwards of 800 feet ; the length of the tubes was di- 
minished to 4 ft. 9 in., and the total surface was reduced to about 500 feet, when it was found that a 
saving in fuel of 40 per cent, per ton per mile moved was produced, with a saving of 23 per cent, per 
mile run ; the coke used per ton per mile, with long tubes before alteration, being -504 lb., and with the 
short tubes, -298 lb. 

The back pressure was contended to he a serious drawback to the long-tube engine, and an example 
was given of a trial of a single engine ou the new plan, against two of the ordinary kind, of 170 tons 
in both casts, and, although the single eugine was 43 per cent, less powerful than the two engines to- 
gether, and had 20 per cent, less heating surface, yet it had performed the same distance of ] ] 1 miles 
in ten minutes less time, and with 3 lb. per mile less fuel. This, it was argued, was owing to the en- 
gine exerting a greater dynamic force, by being relieved from the back pressure of the blast-pipe, which 
in the case of the other two was applied to force the fire, and to draw the heated air through the long 

By the mode of placing the tube plate some distance within the cylindrical part of the boiler, the 
tubes were not liable to be choked with cinders, or the draught to be obstructed. This plan also afford- 
ed an opportunity of reducing the size of the tubes from 1| inch diameter to If inch, giving in the 
same boiler an equal area of flue passage, whilst at the same time the proportion of tube heating sur- 
face was increased 34 per cent, per foot of length of tube, and a very large addition of flame surface 
was gained. 

It was further argued that although the evaporation of water per lb. of fuel was the test of tho 
boiler, yet up to this time, few if any experiments could be implicitly relied upon, owing to the quanti- 
ties being estimated by measurement instead of by weight, and without due regard to the variation of 
the temperature of the water in the tender. 

As to the evaporative powers of marine boilers as compared with that of the best locomotive boilers, 
If an investigation was instituted it would be found that the general features of the best tubulir marine 
boilers now used in ocean navigation were nearly identical with those of locomotive boilers, but the 
circumstances under which they were used were very different. In the marine boilers, coal was used 
instead of coke, and the natural draught of the chimney instead of the urging of the blast-pipe ic » 



locomotive, worked for many weeks or months consecutively, without the means of stopping for any ex- 
tensive repair, or even to he cleaned except at long intervals. The following statement showed the 
comparative proportions and effect of the two descriptions of boilers : 

In the Locomotive Boiler, 
1 square foot of firegrate consumed about 112 

lb. of coke per hour. 
1 square foot of firegrate required about 85 

square feet of firebox and tube surface. 

In tJie Marine Boiler, 
1 square foot of firegrate consumed about 20 lb 

of coal per hour. 
1 square foot of firegrate required about 30 

square feet of fireplace and tube surface. 

1 square foot of firegrate with the above surface 1 square foot of firegrate with the above surface 

would evaporate 1008 lb. of water per hour. would evaporate 170 lb. of water per hour. 

1 square foot of flue surface would evaporate 1 square foot of flue surface would evaporate 

11*7 lb. of water per hour. 5-66 lb. of water per hour. 

1 lb. of coke would evaporate 9 lb. of water. 1 lb. of coal would evaporate S'5 lb. of water. 

1 n. P. of 33,000 lb. lilted 1 foot high per min- 1 h. p. of 33,000 lb. lifted 1 foot high per minute, 

ute, required about 4 lb. of coke per hour. required about 4 - 25 lb. of coal per hour. 

From this statement it appeared that although the proportion between the firegrate and the flue 
surfaces was widely different, the quantity of water evaporated, and the power obtained by the 
consumption of a given weight of fuel, was nearly the same, when allowance was made for the difference 
in the evaporative power of coal and coke. The possible maximum evaporative power of 1 lb. of 
wbon, was deduced from the results of chemical experiments, showing that 1 lb. of carbon, converted 
into carbonic acid, developed 14,000 units of heat, or would raise 1-1, 000 lb. of water through V, which 
was equivalent to the conversion of 12 lb. of water at 60' into steam of 120 lb. 

A comparison was drawn between the recent experiments of Mr. Marshall, on the large firebox 
engine, and those on the long boiler engine, made during the Gage Inquiry, the results being with the 
former a consumption of 40 lb. per mile with an average load of 64 tons, and with the latter a 
consumption of 27 lb. per mile with a load of nearly 60 tons. The recorded results of the work of 
the passenger trains on the Eastern Counties fine, for the last hah" year, showed an average consumption 
of coke under 18 lb. per mile run. 

It was contended, that hitherto no advantages had resulted from the extension of the firebox and the 
reduction of the length of the tubes, still it was possible that this innovation might, by directing 
attention to the subject, lead to important modifications of the structure of locomotive boilers, 
which should possess compactness, lightness, power of raising sufficient steam with rapidity, for perform- 
ing the required work, strength to resist the chance of explosions, and a form calculated to diminish 
the disastrous effects of explosions when they occurred, facility of repair, especially of the firebox, 
which was the part most liable to deterioration, being most severely acted on by the fire, and also 
requiring more support than the tnbes, the latter being at the same time cheaper and of thinner metal, 
whilst by an extension of their length the diameter of the external shell of the boiler could be dimin- 
ished ; the firegrate should not be larger than would evaporate the required quantity of water into steam, 
within a given time, with the utmost practical economy of fuel, and if that were accomplished, it was 
"f little importance whether the evaporating heat was communicated through the firebox or by the 
tube surface ; and that up to the present time the results of the experiments upon the boiler with 
enlarged firebox and shortened tubes, exhibited rather a retrograde step than an onward progressive 

From the "Report of G. W. Whistler, Jr.," upon the use of Anthracite Coal in Locomotive Engines 
on the Reading Rail Road, made to the President and Directors of that company, in 1849, we extract 
the following : 

Tabulated Comparison of Engines on Heading E. E. — Fuel Consumed. 

Class of Engines. 








T . 



c ^ 



- 1 





'S ° 




£= ' 


3 © 


— .£■ 


Baltimore Anthracite Engines. 







8.-46 ill. 





9 tons coal. 

14,400 galls. 

Wood .tngines, .Laree. 

8.- " 





13.75 c'dsw'd 

16,200 " 

" " Small. 

6.- " 





13. " " 

The total weight of the Baltimore engines with coal, fuel and water, 27 tona ; weight on eight 
iriving wheels, 25 tons ; do. on two small trailing wheels, 2 tons ; diameter of the boiler, 42 inches 
length of tubes, 14 feet; diameter do. 2 J inches ; area of grate, 18 feet ; fire surface, 957 feet ; diame- 
ter of cylinders, 16'5 inches; length of stroke, 20 inches. The draft is regulated by the variable 
exhaust in the smoke stack — steam cut off at half stroke. 

The large 8 wheeled wood engines — total weight 22'5 tons ; cylinders 15 - 5 inches in diameter ; 20 inch 
stroke ; fire surface about 875 feet ; and of grate about 12 feet. 

The essential point in which the Baltimore engines differ from the wood engines is in their having i 
much larger fireplace and area of grate for the combustion of coaL 



The principal item of excess of cost for repairs of engines burning coal over those burning wood, ij 
caused by the destructive effects of a coal fire upon the inside sheets of the fire-box; and when iroE, 
(the soundness of which is always uncertain from the manner in which it is at present made,) has been 
used entirely for fire-boxes, the intense local heat has very soon blistered and burned away the sheets in 
the immediate vicinity of the coal fire. Another destructive effect from the use of coal is its severity 
on the laps or joinings of sheets in the fire place. To obviate this, copper sheets were substituted for 
iron for a distance of two feet above the grate. The experience on the Reading Railroad with anthra- 
cite coal has developed a rapid and unexpected destruction to the copper sheets, from the mechanical ac- 
tion of sharp particles of coal, which fleck off from the fresh coal when suddenly heated, and impinge 
upon and cut away the copper sheets forming the sides of the fire-place. The extent of this mechan- 
ical action is very limited, about fourteen inches in width through the entire length of the fire-place^ 
seven inches above and the same below the surface of the coal fire. In the line of the stay bolts both ver- 
tically and horizontally, the copper retains its original thickness ; and upon the copper sheet below- the tube 
or flue sheet there is no indication of wear, for the particles of coal which are earned towards the tubes 
bank against, and protect this sheet. On the "Baltimore" the copper lasted fourteen months, about one 
third of the time experience had proved similar fire-places to last in engines burning bituminous coal 
on the Baltimore and Ohio Railroad. In addition to the extra wear of Sre sheets, the occasionltl melt- 
ing of grate bars, the increased liability to leakage, the wear and destruction to the ends of the tubes 
by caulking, &c, and the accumulation and igniting of fine coal in the smoke box, all produce their 
share of extra expense for repairs over wood burning engines. 

Experience of the Baltimore and Ohio Railroad in the use of coal for locomotive engines. 

Table showing the amount of Fuel consumed on the Baltimore and Ohio Eailroad, at different periods from 1388 
to 1843.. 


Weight of Engine 
on Driving Wheel.. 

Position of Boiler. 


Miles run. 



4 Tons 


23 Tons 


1.15 Tons Anthracite. 


7.5 " 

45 " 


1.25 " 


8.5 " 


50 " 


1.5 " 


10.5 " 

00 " 


1.25 " 


10.5 " 

60 " 


1. " Bituminous. 


9.75 " 


60 " 


1.65 " 


6.5 " 


40 " 


2.05 Cords of "Wood. 


19.33 " 


140 " 


3.13 Tons Bituminous. 


8.25 " 


00 " 


3.13 Cords of Wood. 


23.5 " 

225 " 


3.25 Tons Bituminous. 


10.5 " 


60 " 


1.25 " 


10. " 


60 " 


1.03 " 


10. " 


0:1 •' 


2.75 Cords of Wood. 


10. " 


00 " 


1.5S Tons of Coke. 


23.5 « 


200 " 


2.25 " Bituminous. 


23.5 " 


■_•:.-. ■■ 


1 ton of Bituminous coal = 1.25 tons Anthracite coal. 

1 ton of Bituminous coal = 2.12 Cords of Wood. 

1 ton of Anthracite coal = 1.75 Cords of Wood. 
By an examination of this table, it will be seen what experience alone can do in reducing expendi- 
tures ; for it will be easy to detect the same engine through a period of years, and see her progressive 
economy in the consumption of fuel. Time and experience alone have accomplished this, and much 
may be expected for the Reading Railroad, when by a more general use of anthracite coal, it shall be 
regarded less as a matter for experiment, thau an important element of railway success to be perfected 
with care and attention. 

Extra cost per year over Wood Engines for each 23.5 ton Coal Engine on the Baltimore and Ohio 
Railroad from the use of Bituminous Coal : 

Cost for renewing fire-place ......... si 00.00 

Two sets c' fire bars, 1000 lbs. cast iron, at 2+ c. 25.00 

Renewing ends of Tubes, caulking, &c. 100.00 

Extra work, caulking, &c. .......... 25.00 


By these experiments and dates from the Reading and from the Baltimore and Ohio Railroads, it was 
satisfactorily proved, even at the date of the report, 1S49, that in an economical point of view coal en- 
gines are superior to those burning wood. Since that time further improvements have been made, and 
at present almost the entire hauling of the Baltimore and Ohio, the Reading, the Pennsylvania Central 
and their connections, and the Brant h Coal Railroads, is performed by coal engines, either anthracite 
or bituminous. 

Marine Boilers. — We are very much in the dark as to the true principles upon which to design a 
marine boiler, which shall produce the greatest effect with the least stowage, and first cost, subsequent 
labor, and fuel. The best that can be done is to determine which of these considerations shall have the 
least weight, and to be governed accordingly, looking as a guide to practice, rather than any assumed 
theoretical principles. The object aimed at in marine boilers is, in general, to reduce the space occu- 
pied by the boilers to the least possible, consistent with the effect to be produced, and at the same time 
not to lose sight of the necessity for proper space for cleaning and repairing. A certain proportion 
between the area of the grate and the total heating surface has been found productive of the best re- 



suits, with a given description of fuel, but an alteration in the quality of the fuel used will t>e found to 
affect this result materially. 

Again, the famed Cornish boiler, which has exhibited the greatest amount of work with the least 
fuel, is arranged on the principle of slow combustion, and an extended flue surface, while the locomo- 
tive boiler, on the contrary, is dependent for its effect upon a quick combustion and a short and direct 
draught. Hence we see the improbability that any one form of boiler will ever be likely to fulfil all 
the varied conditions under which they may be placed. As before remarked, for stationary boilers the 
general proportions have been measurably determined — that is to say, for every cubic yard of capacity 
in the boiler, there shall be a square yard of fire-surface, and a square foot of fire-grate, and one-half 
dhe contents of boiler to be water, and the other half steam room. These proportions have given good 
results, but are too bulky for economical stowage on shipboard, and as constructed for land use, are de- 
ficient in steam power. 

Marine boilers are of necessity either flue or tubular boilers, since the flame must be within the shell 
of the boiler ; but in this arrangement they are almost as various as the makers. The evaporation of 
marine boilers per lb. of coal is considerably less than that of stationary boilers ; reckoning the latter at 
from 8 to 10 lbs. of water evaporated per lb. of coal, that of marine boilers will be from G to 8. The 
proportion of fire surface to grate, taken from an average of Go boilers in Bartol's Marine Boilers, is 28 
to 1 ; of grate to area of chimney, 6.3 to 1 ; the amount of coal consumed per hour per square foot of 
grate, 26 lbs. The boilers from which an average is thus taken include about all the varieties used on 
our river and ocean boats, and of which we now proceed to give examples of some of the most im- 

BOILERS, American. The intense heat produced by anthracite coal cannot be observed in steam- 
boilers, except by its effect in the amount of steam generated. 

Many persons, remarking the much greater volume of flame in puddling and other furnaces, have 
attributed the difference to the superior arrangement of the furnaces, aud have anticipated great results 
from the adoDtion of the same plan in steam-boilers. 

[Fig. 414 The steamboat '"New 
York," built by H. R. Dunham and 
to)., has one copper boiler, one en- 
gine, 40-inch cylinder, ?j stroke ; en- 
tire surface, 16084 viz.: 

Burns anthracite coal, without a 
blower, at the rate of half a ton per 
hour; keeps 12 inches steam, cuts 
off at h ; 250 2£-inch lubes. 

Now burns wood, on account of 
injury to the copper by the anthra- 

This erroneous conclusion is the result of ignorance, or of inattention to the fact that in steam-boilers 
the flames are partially extinguished by coming in contact with surfaces, comparatively cold, highly con 
ducting, since the heat of the metallic plates of the boiler can never be much above the boiling point 
of water; whereas, the walls of the furnace being non-conductors, and of consequence almost of the 
temperature of the furnace, inclose all the heat, and produce naturally a different appearance in the 
flame. The intensity of the heat generated in any furnace or boiler by a given amount of fuel, depends 
alone upon the velocity of the current of air; or, in other words, upon the amount of oxygen brought 
into contact with it. without any reference whatever to the way in which the heat so generated is dis- 
sipated or disposed of. 



Stevens' boilers —A complete revolution has taken place during the. last ten years in the form of the 
boilers of steamboats plying on the lakes and rivers of the Northern States ; this change is the result o{ 
the introduction of anthracite, and the many experiments made to discover that form of grate and aoder 
best adapted to its combustion. 

The editor has collected, with considerable labor and care, all the best forms, selecting such only as 
experience 1ms approved and extensively adopted. These are laid down in as plain a manner as pos 
sible, sections of each showing their general structure. 

In the year 1S37, Robert L. Stevens, Esq., constructed a pair of boilers, of tubular form, for his steam- 
boat " Independence," plying between South Amboy and New York, of which Figs. 415 and 416 
are correct representations, the form of which was well adapted to the burning of the new species of 
fuel by the assistance of bellows, or what is ordinarily termed the fan. 

No difficulty was ever found in the accomplishment of the purpose they were intended to effect, and 
though many improvements have since that time been adopted, they are still working satisfactorily. 

To Mr. Stevens belongs the credit of first establishing the water-bridge ; which serves the purpose 
of protecting the mouth of the tubes, and preventing the heat of the furnace from burning them out. 
This is one of the most important features of Mr. Stevens' arrangement, and has since been adopted by 
many other engineers. 

Another curious and useful form of boiler is shown by Fig. 414, two of which were built by Mr 
Stevens for the steamboat " New York." 



The shell or crown is nearly of the form of a parabola, beautifully adapted to the end designee 
See Fig. 417. . 

With a very great expansion of surface and great breadth of furnace below, there being a small 
quantity of water for so large a generating surface, saving a great deal of weight, which is of great im- 
portance, particularly in river boats, this boiler has the advantage of being easily braced, and the centre 
of gravity being very low down, — a happy and important arrangement in the boats on the Hudson, in 
which the boilers are placed on the guards of the boat on deck. 

Several examples are added to illustrate similar and other methods. 

Fig. 417 is a boiler, built by H. R. Dunham and Co., for steamboat " New York" 

Four of this, Figs. 418 and 419, for steamboat "Empire," built bv T. F. Secor and Co., which has 
two engines, each of 43-inch cylinder, 12 feet stroke, and uses anthracite cal, with blowers. 



Figs. 420 and 421. The steamboat "Belle", built by T. F. Secou and Co., has 1 engine of 50-inch 
cylinder, 10 feet stroke; 13fi cubic feet in cylinder, which gives, in proportion to the boiler, lly/j to 1 
Uses anthracite, with a blower. 421. 


Fire surface in this boiler. 

In the steam chimney 12-000 

" front connection 85"039 

" return flues 477062 

" back connection 114'000 

" main flues 621-028 

" furnace, bridge-wall, &c 21S-052 

Total number of square feet in boiler 

Two of this, Figs. 422 and 423, are m use in the steamboat " Columbia," built by T. F. Secok anu 
Co. She has one engine, 43-inch cylinder, with 11 feet stroke. Ill cubic feet in cylinder, which giyea 
ISJyY to 1. Uses anthracite, with blowers. 

Fire surface in this boiler. 

In the furnace, &c 163028 

Main flues 311000 

Back end connection 750S7 

Return flues 241-014 

Front connection 63-107 

In the steam chimney 7'065 

Total number of square feet in boile- 860-391 



One of this, Figs. 424 and 425, for two high-pressure engines, built by T. F. Secor and Co., in use 
for a screw propeller boat, with 20-inch cylinders, and 2 feet stroke. S cubic feet in cylinders, which 
gives 68 to 1. Uses anthracite, with blowers. 

Fire surface in this boiler. 

Furnace 59-103 

Main flues 228081 

Back end connection 48'045 

Return flues 179-072 

Front end connection 29-110 

Steam chimney 4104 

Total number of square feet in bciler 547'51c 


Two of this, Figs. 426 and 427, in use on steamboat "John Mason," built by T. F. Secor and Co., 
has one engine of 254-in. cylinder, with 6 ft. stroke. Estimated weight of each, 8S34 lbs. Estimated fire 
ttirface, 347 square ft. 21 cubic ft. in cylinder, which gives 33 to 1. Uses anthracite, without blowers- 


Two of tbis, Figs. 428 and 429, used for steamboat " Troy," built by T. F. Secoe and Co., bas tw« 
ingines of 44-inch cylinder, and 10 feet stroke. Uses anthracite. 

Fire surface in this boiler. 

Front of furnace 18 ' 90 

Sides of ditto pOO 

Top of ditto 76-50 

Bridge-wall 18-00 

Between bridge-wall and flues 2000 

Between flues, back and front 17-26 

Large flues 167-32 

Small ditto 408-60 

Return ditto 471-50 

Steam chimney 10-40 

Back end 25-10 

Connection around flues 10200 

Front of return 52-50 

Eeturn U20 

Fire surface of this boiler 1483-32 



Figs. 430 and 431. The steamboat " Globe," built by T. F. Secor and Co., has one engine of 41 
mch cylinder, with 11 feet stroke. 100 cubic feet in the cylinder, which gives 10 T 'A to 1. 
Uses anthracite coal, with a blower. 

Improvements in steam-boilers — By James Montgomery, Memphis, Tenn. These improvements have 
in view an economical mode of using the fuel ; the establishing of a perfect circulation of the water 
through the tubes ; the depositing of sedimentary matter in a receptacle below the fire, and the pre- 
venting of the passing of water, from foaming or other causes, into the steam-pipe and cylinder. 

Fig. 432 is a vertical section through the centre of the boiler, and through the furnace attached 

Fig. 433 is a view of a part of the boiler, supposing the furnace part to be removed, and a vertical 
section to be made of the sectional part in the line X X of Fig. 432 an: at right angles thereto 

Fig. 434 is a top view of the termination of the boiler-tubes, and of tht .shell of case by which ther 
*re surrounded. 

Fig. 435 is a front view of the furnace and boiler. In each of these figures, where the same parts 
occur, they are designated by the same letters of reference. 

The boiler, in that part which surrounds the tubes, is formed of two concentric vertical cylinders, ex- 
cepting where the heat and flame from the furnace is introduced, and where the gaseous products of 
combustion escape to be conducted off by the flue. A is the outer, and A 1 the inner shell of the boiler, 
with a water space A 2 between them. B B are the tubes, which pass through, and are made fast to 



two heads, C C and D D, that are convex upwards. E E is the steam space, and F the water line, 
G G is that part of the boiler which is below the lower tube-head C C, and H H the bottom of the 
boiler. This bottom is convex outwards, and may be either spherical or conical ; and as the direct heal 
from the fiie is never applied to this bottom, the water contained between it and the lower tube-head 
C G is in a state of comparative quiescence, in consequence of which the sedimentary matter which 

forms incrustations on the bottom and other parts of boilers, as ordinarily constructed, will settle down 
in this part in a loose unaggregated state. At I, in the centre of this bottom, is placed a blow-off valve, 
denominated a mud-valve, and which may be opened when requisite, for the purpose of blowing iff the 
accumulated sediment, which it will do effectually without occasioning any considerable waste of water. 
J J is the fire-chamber of the furnace, K the grate-bars, and L the ash-pit. 





ffilllli 1 1 111 






The furnace is placed in such a manner as that the direct heat from it shall enter among the tubes B B, 
■it their upper section, above a diaphragm or partition M M, over which the draft will pass as indicated 
by the arrows, and then into the lower flue space M 1 M 1 , and around the furnace to the chimney 



Tbe furnace is surrounded with a water space P P, which communicates with the water in the boil 
ers. This furnace may be placed lower down if desired, and the heat be made to impinge directly on 
the lower part of the tubes, but we are well assured that the arrangement as represented will be found 
to be the best. 


i i5s5I^^S 

! i 

Below the upper head of the boiler is placed a metallic shield Q Q, leaving an annular steam spact 
ef a few inches around it, which will, in a great degree, repress the foaming of the water when tl.£ 
pressure is taken off by the admittance of steam into the cylinder, and will thereby prevent the injuri- 

ous, and frequently destructive, result of the entrance of water with the steam. Under this arrange, 
ment i.f the shield, the steam is drawn equally from all parts of the circumfeience of the boiler. 
The production of a free and perfect circulation of the water in a boiler lias frequently been air.ied 



at, but has not, we believe, been heretofore attained. But by this plan of arranging the parts of the 
boiler in such a way as that its bottom shall not be subjected to the direct action of the heat, and of 
introducing it laterally among the vertical tubes, we not only allow of the depositing of the sediment as 
otated, but cause a decided and rapid circulation, preventing all incrustation on the interior of the tubes, 
and augmenting the generation of steam. To clean out any ashes that may accumulate around the 
lowar ends of the tubes, an opening, closed in the manner of a man-hole, must be prepared, as 
at R, or in any other convenient situation. S S S, Fig. 435 are the ordinary openings into the fire- 

The improvements in this patent consist in arranging the fire-chamber or furnace of a tubular boiler 
at the side, so that the heat shall act on the upper half of the tubes, in combination with a diaphragm 
or partition, and flue to carry off the flame, heated air, etc., to act on the lower half of the tubes after 
acting on the upper half, as herein described. 

The patentee also claims the making of the bottom of the boiler of a conical or dished form, with a 
mud or blow-off valve in the lowest part of the concavity, in combination with the vertical tubes com 
muuicating with the bottom in the manner herein described, to permit the deposit of the sediment, 
there being a water space surrounding them to induce a circulation of the water up the tubes and dowr 
the surrounding water space, to wasli the sediment towards the mud or blow-off valve, as herein de 

Steamship Ospreys boilers. — These boilers, represented in Figs. 436, 437, and 43S, were built 
early in the spring of 1S50, and are the same, in general arrangement, as that of the Earl of 

A A, fire-doors ; B B, ash-pits ; C C, furnaces ; D, vertical tubes ; E, flue, in all the figures. 

Sailers of the steam-ships Atlantic, Pacific, Baltic, and Arctic — Figs. 439 and 440. — The only dif- 
ference between these boilers and those of Dundonald is in the furnaces, which are here double, one 
being above the other, caused by the necessity of obtaining more grate surface than could be obtained 
with one range of furnaces, the objection that had been urged against allowing the heat to act against 
the whole length of the tube having, by experiment, been found to be without cause. 

A A, fire-doors ; B B, ash-pits ; C C, furnaces ; D, vertical tubes ; E, flue, in both figures 

Improved steam-boiler — By "Wm. E. Milligan, New York City. Fig. 441 represents the boiler, 
ihe nature of this invention consists in a new arrangement of flues, tubes, and water spaces within a 
boiler for generating steam, whereby is presented a much enlarged amount of surface to the action oi 

The construction is as follows : Tire general external appearance of this boiler is as of usual mane, as 
is also the construction and arrangement of the furnace within it, but upon the upper side of the fire- 
place a is placed a series of fves i, of a numbor and capacity sufficient to carry off readily the products 



of combustion from the furnace. These flues open into a horizontal flue c, which is placed above the 
furnace and below the water line of the boiler. Back of the furnace a, and near to the bottom of the 
boiler, is another horizontal flue d, and between these horizontal flues is a series of vertical flues, similar 
tr the flues b, but necessarily longer, as shown at E, and these flues are for the purpose of conveying 
the products of combustion from the upper to the lower horizontal flue. Through the centre of each of 
the vertical flues E is placed a tube/, of, say, one half the diameter of the flue, and these tubes extend 
from the upper tube-sheet of the horizontal flue c, through the lower tube-sheet of the flue d, as shown. 
The water passes through these tubes, and the purpose of them is to present greater surface for the 
absorption of heat, as well as to insure the circulation of the water within the boiler. From the lower 
horizontal flue d, the product of combustion is either conveyed directly into the chimney, or it may be 
returned to another upper flue c', through the flues E' ; thence again to another lower flue d', through 
the flue E"; and thence into the chimney by means of the flues 6', as shown; one, two, or more fur- 
naces arranged with flues and tubes thus constructed, may be placed within the same shell, sufficient 
space being left between them, as shown, for the circulation of the water. 

The practical operation is this : The water in the boiler rising above the upper horizontal flue fills 
the tubes/, and surrounds all the flues. The product of combustion passes from the flue c through the 
vertical flues E, parting with its heat on the one side to the water surrounding those, and on the other 
to the water within the tubes/ The water" contained in the tubes is much more rapidly heated than 
that surrounding the flues, as its volume is less, and hence by known laws a regular and perfect circula- 
tion takes place within the boiler. 

The patentee does not mean or intend to limit himself to the precise form of construction herein set 
forth, as it is obvious that if desirable the flues c and d may be placed vertically, and the others may 
be horizontal. 

What the patentee claims as his own invention is the general arrangement of the tubes and flues of 
the boiler in the manner described ; that is to say, the water tubes connected with an upper and lower 
tube-sheet, in combination with the flues of less length than the tubes, which flues are also connected 
with an upper and lower flue-sheet, whereby two horizontal flues are formed in such connection with 
each other by means of the vertical flues, that the product of combustion from the fireplace shall pass 
into the upper horizontal flue, and thence down the vertical flues into the lower horizontal flue, having 
thus the facility of parting with its heat on the one hand by radiation through the flues to the water 
spaces surrounding them, and on the other through the tubes to the water circulating through those ; 
and this whether the said tubes and flues are placed vertically or horizontallv 
A. 442. B. 443. C. 444. 

Boiler invented by E. A Bourry. Figs. 442, 443, 444. 

The aim of the inventor of this boiler has not been, like with many others, to obtain an incredible 
saving of fuel, but to insure great safety, combined with restriction of space and cost. 

The cylindrical form of boilers is the best adapted for high-pressure steam : and the smaller the 
diameter, the more the boiler will be able to stand. Boilers of small diameter have been in use these 
many years with great success, for the working of stationary engines, but on board of vessels they are 
scarcely applicable, because — 1st, Boilers are required with internal fire ; 2d, such boilers must be in 
great number, which occasions a very awkward disposition and management; and, 3d, a given quantity 
of fuel is burned more economically on one large grate, than on several small ones, as with the former 
it requires less draught, and the combustion is more complete. 

Now, to combine a boiler of a small diameter, with a large heating and grate surface and internal 
Gre, seems at the first sight to be next to impossible, and yet this boiler embraces all those qualities. 


A is a cross-section through the fire and smoke bos ; B is a front view ; and c is a longitudinal sec- 
tion, showing the whole internal arrangement. The boiler consists of two cylindrical parts, placed 
above each other : the lower part contains the fire-box, bridge-wall, and main-flues ; the upper one con- 
tains the return- flues, smoke-box ; and steam-room. If space or convenience require it, the boiler may 
be made much shorter, in dispensing with the main-flues, in which case the return-dues can be made 
of a smaller diameter. It will be seen in the drawing, that the two cylinders are not entire, but are as 
if a slit was cut out on each of them, all the way along, and both joined there together, which leaves a 
free passage to both water and steam. But as, at the junction of both cylinders, the boiler would have 
a tendency to open outwards, this is prevented by a strong iron bar being placed in each hollow, and 
both kept securely together by a number of traversing bolts a. 

', - The boilers of the Atlantic and Pacific, of the Collins line of 

ocean steamers, are designed from that of Lord Dundonald, patent- 
ed in England, Jan. 19, 1843, a longitudinal section of which is 
here shown, (Fig. 445.) 

The earl says, " This figure shows a section of apparatus for 
generating steam for steam engines, constructed according to this 
part of my invention, and the apparatus is composed partly of 
tubes or hollow surfaces, the interior of which are open to 
the water spaces of the boiler, with which the tubes are com- 
bined. Such boiler or outer vessel may be varied in shape so long as there be a chamber as here- 
after described, between the furnace and the fire-place and the chimney. K K is a steam boiler, 
which may be of a square or cylindrical section, or other convenient figure ; L is the fire-place, 
M M M M is a rectangular chamber, there being a number of tubes or hollow surfaces in the upright 
position, through which the water flows in consequence of the water therein becoming hotter than 
other parts of the boiler. The heat of the fire passes into the chamber M at N, over the bridge 0, at 
the end of the furnace or fire-place ; and the passage P, from the chamber M into the flue or chimney, 
is situated as low as possible, in order that the greater heat of the vapors may be retained in the 
chamber M M, for it will be readily understood that the more highly heated vapors or products of com- 
bustion will occupy the upper part of the chamber M M, and the draught into the chimney will only 
carry off the cooler parts of the vapors, the more highly heated being comparatively in a quiescent 
state, at the upper part of the chamber M ; and it is the peculiar arrangement of the chamber M 
within a steam boiler, when containing tubes or hollow surfaces, and combined with the outlet P into 
the chimney, so as to leave a considerable space above it (for the more highly heated vapors to be 
regained in the chamber M), which constitutes the peculiar character of my invention. Z is an opening 
into the chimney at the upper part of the chamber M M, to facilitate the getting up of a draught when 
fi'-st lighting a fire, it being closed at all other times ; Y is a steam pipe in connection with the upper 
part of the boiler, having a stop-cock ; this pipe is drilled with many small holes in the direction 
towards the chimney, by which numerous jets of steam can be projected amongst the tubes, in order to 
Siveep away the dust and ashes when required. I would remark that it is not necessary to have the 
tube') in an upright position." 

Such is the Earl of Dundonald's account of his invention. This boiler is superior to all that have 
preceded it, and is identical with those now in use on board the steamer Osprey, with the exception that 
her boilers have not the opening Z, or the steam pipe Y, both of which would be an improvement. 

In December, 1845, Jas. Montgomery took out his patent for a tubular boiler, of which a description 
has already been given, the distinguishing feature of which is a horizontal diaphragm placed about 
midway in the tubes. Several of these boilers were introduced into vessels of moderate size, and several 
were employed for stationary purposes, and effected a considerable saving of fuel when they had 
supplanted ot— 3r boilers. 

The success attending the Montgomery boiler in this country called the attention of those interest- 
ed in marine navigation to them ; and when the steamers Atlantic and Pacific were begun under the 
direction of Mr. E. K. Collins, of New York, he caused a large number of experiments to be made with 
vertical tubular boilers for use in salt water. The performance of the steamboat Jonas C. Heartt, with 
Montgomery's boiler, was carefully noted for several days, being equal in time to a trip to Europe. 

It being satisfactorily ascertained that the tubes would not choke up, but, on the contrary, would 
keep perfectly free from scale, Mr. Collins concluded to adopt some form of vertical tubular boiler, and 
determined to test the use of vertical tubular boilers — in fact, the boiler of Dundonald. After a series 
of experiments, proving that there was no objection, the boilers of the Atlantic and Pacific were 
designed by his chief engineer, John Farron, jr. 

The only difference between these boilers and those of Dundonald is in the furnaces, which are here 
doubled, one being above the other, caused by the necessity of obtaining more grate surface than could 
be obtained with one range of furnaces, the objection that had been urged against allowing the heat to 
act against the whole length of the tube having, by experiment, been found to be without cause. 

Tubular boilers have suffered much in reputation by being made too contracted in the water-ways, 
the tubes too close together, and the plates not sufficiently strong to resist the increased pressure used 
in them. They save both in weight and space, and are now designed quite free from the general ob- 
jections made to them ; they are not more expensive in fuel when a due proportion exists between the 
absorbent surface and the surface of the grates ; and there is no reason why they should not be as dura- 
ble as the ordinary flue boiler ; they perhaps require more attention in blowing off, and keeping free 
from salt and earthy incrustations. 

English Marine Boilers. — Figs. 446, 447, 448 and 449 are different views of the boilers of the steamer 
Phoenix, a steamer constructed by Messrs. Scott, Sinclair & Co., for plying between Capetown and Al- 
goa Bay, at the Cape of Good Hope. This vessel was provided with collecting vessels within the boi- 
ler for obviating the deposition of scale. 





; 0DO 

Kcalk.— l-16th inch = 1 foot. 

Scale.— 1-I6th inch = 1 foot. 

Scale.— l-16th inch= 1 foot 

Scale.— 1-lGth inch = l foot. 
Longitudinal Section. 

Scale. — 1-lCth inch:= 1 foot. 

Elevation and Transverse Section. 

Figs. 450, 451, and 452 represent the boilers of the Achilles steamer, constructed by Messrs. Caird & 
Co. This vessel plies between Liverpool and Glasgow, and is well known lor her numerous excell- 




Scale. — 1-lGth inch= 1 foot. 
Longitudinal Section and Exterii 

Scale. — l-16th uich= 1 foot. 
Horizontal Sections and BirdVEye View. 

Fig. 453 represents the boilers of the sister ship, the Eagle, also by the same makers. There is 
nothing of peculiar excellence in these plans ; and, for steam vessels, we believe boilers of this kind 
will be superseded by the tubular plan of boiler, of which we shall give all the best specimens. But 
a good number of boilers upon the common flue plan are still made, so that some specimens of them 
are indispensable ; and, indeed, there are still far more flue-boilers in use than there are of any other de- 
scription. In most of these boilers it is a fault that the furnaces are made too long and narrow, and the 
consequence is, that it is impossible to fire them on a long sea-voyage, especially in stormy weather. 
It is much preferable to restrict the furnaces to a moderate length, and give the bars a considerable 
elevation, so that they may always be well covered with coal at the after ends. When the furnaces are very 
bug, a good deal of air generally escapes into the flues at the after end of the bars, the effect of which 
is materially to lessen the generation of steam. 

Figs. 454, 455, and 456 represent the boilers of the Thames and Medway, two vessels of large size, 
constructed by Messrs. Maudslay & Field for the Mail Steam Packet Company. The boilers of these 
vessels have been very successful, and are among the best specimens of the flue-boiler as applicable to 



%! U 



I J 


! 1 

Horizontal Section through 

marine engines hitherto produced. We do not know 
of any boiler of this kind that engineers may imi- 
tate with greater safety, as regards their power 
of generating steam, though there are many speci- 
mens distinguished by a greater durability. In 
some of the boilers recently introduced in the Mail 
Steamers, the furnaces stand athwartships, and the 
plan is attended with the material advantage that 
the coals trim more easily ; for the coal reserve in 
this arrangement situated behind the boilers, and 
another depot standing between the boilers and the 
engines, communicate immediately with the stoke- 
holes, whereby an easy transfer of the coal becomes 

Figs. 457 and 458 are also views of the boilers of 
the Thames and Medway. These views are per- 
pendicular sections through the lines A B and C D, 
shown in the horizontal section through the furnaces, 
and the horizontal section through the flues. The 
dotted sweeps at the two upper corners represent 
the ascent of the flue into the funnel. The flue 
narrows in width and rises in height as it approaches 
the chimney, for the same area is not required for 
the transmission of the smoke after its volume has 
been contracted by the communication of heat to 
the water, and a less depth of water above the flue 
suffices after the heat of the smoke traversing it 
has been well-nigh expended. The bridges are 
water bridges, and then - superior ridges do not 
run in a horizontal, but in an oblique direction, the 
design of which is to facilitate the extrication of 
the steam. There are four boilers in all, and the 
boilers are fired from both ends. 

In furnaces with two lengths of furnace-bars, it is a good plan to make the centre-bearer double, so 
that the ends of the bars may have a space between them through which the ashes will be precipi- 
tated ; the space thus left enables the bars to expand without injury on the application of heat, whereas, 
without some such provision, the bars are very liable to get burned out by their centres bending up into 
the furnace, or else the lugs which carry the bearer -bars will be perpetually being carried away. A 
similar space should be left between the fore end of the bars and the dead plate at the furnace mouth, 
and care should he taken that not only the ends of the bars do not touch, but that the heels of the bars 
do not rest against the furnace-bearers. 

I.en-iniiliiKil S--cli 

. t " 

Scale. — l-6th inch = 1 foot. 
Section through A B. 

Scale. — 1-clh inch = 1 foot. 
Section through CD. 

The bridges of these boilers arr it will be observed, of brick, and come tolerably close to the fcr- 
lace top. In such cases it is expedient to make the upper part of the bridge consist of one or two fire- 
brick blocks, which may be lifted off when a person requires to enter the flues to sweep or repair them. 
The continual knocking down and building up of bridges becomes otherwise very expensive. In boilers 
sf this construction it is difficult to fight one tier of fires after the others have been thoroughly kindled, 
its the fires first lighted keep the lead in the draught. It might be anticipated that by firing tli2 tiers 
of fires alternately, the smoke would be burned, but such is not found to be the effect. 


Provision has been made in these boilers for the introduction of a fan- blast, which would at once 
cure the evil of a defective draught. The furnaces would, in this plan, be made close, and the blast would 
be introduced into a chamber at the back of the ashpit A, Fig. 461, from whence it would pass into the 
ashpits by necks AAA, Fig. 459. One inconvenience, however, of a fan-blast thus applied is, that the 
smoke comes out of the furnace-doors very much when they are opened. 

Almost every engineer has made tubular boilers that were short of steam, but we never before met 
with one who acknowledged it. 

The original boilers of the Great Western contained of flue surface 2950 square feet, and of furnace 
surface 890 square feet, making 3S40 square feet of heating surface ; area of fire-grate 202 square 
ieet; capacity of steam-room 1150 cubic feet ; weight of boilers and steam-pipes 202 tons; weight oi 
water SO tons; average consumption of coal 1000 tons per voyage, out and home, of 27 or 23 days, 
[n the tubular boilers, Figs. 459 to 461 the tube surface is 5900 square feet, smoke-bos surface S30 
square feet; furnaces 420 square feet; making 7150 square feet of heating surface; area of fire-grate 
145 square feet; weight of boilers 56 tons; weight of water 52 tons: capacity of steam-room 1320 
cubic feet . average consumption of coal per voyage out and home, of 29 days, 696 tons. The speed of 
the vessel, it will be observed, has somewhat declined with the new boilers, but there is a greater econ- 
omy in fuel upon the same distance. The horse power of the Great Western is about 400 ; the par- 
ticulars of the two boilers will therefore stand as follows : — 

Old Boiler. New Boiler. 

Heating surface per horse power 9'6 17'875 

Fire-grate per horse power '5 '3625 

Steam-room per horse power 2-S75 3 - 3 

Coal per hour per horse power 8'333 5-6 

The consumption of fuel, as here set down, it must be borne in mind is that of the old boiler in its super 
annuated state, and of the new boiler in its best state. The old boiler, when new, did not consume 
more than 6 lbs. of coal per horse power per hour. 

The tubes of these tubular boilers are of iron of 3 inches internal diameter, and 8 feet in length. 
The furnaces are S feet 3 inches in length, which is, in our judgment, a greater length than can be fired 
effectually on so long a voyage as the Great Western has to perform. The water within the boiler 
rises some distance above the top tubes. It would be better, we think, to let the return tubes go through 
the steam, winch would dry it very effectually, and surcharge it in some degree with heat. This could 
easily be done by lowering the water-level, and the hot air will be sufficiently cooled, after passing 
through the lower tier of tubes, to prevent any injury to the upper tier from an excess of heat. One of 
the advantages of iron tubes is, that they can be subjected to a degree of heat, with impunity, that 
would be unsafe to apply in the case of brass tubes. It is said, however, that the scale adheres to 
them with greater tenacity than to brass, but this objection is not likely to prove of much weight if the 
boilers be well blown out, for in that case very little scale will be formed at all. 

Figs. 462 and 463 represent the boilers of the British Queen steamer, constructed to ply between 
London and New York. There is nothing very peculiar in this kind of boiler ; and, indeed, it is nothing 
more than the common marine boiler, as used for the ordinary coasting vessels, constructed upon a larger 
scale. There are four boilers in the vessel, ranging athwartships, containing in all fourteen furnaces, 
the wing boilers containing four furnaces each, and the midship boilers three furnaces each. The pro- 
jection of the water-space into the flues at the after-end of the wing boiler is to obviate a back-draught 
in the furnaces, in consequence of the currents of hot air meeting one another in a direct antagonism at 
the point where they coalesce, and which they would do but for this protuberance, which deflects each 
of them sufficiently to make it enter, without conflict, the longitudinal flue. These boilers were kept 
supplied with fresh water, as the engines are fitted with Hall's condensers, which return the condensed 
steam to the boiler to maintain the water-level. This species of condenser is now discontinued in most 
vessels, as its weight and expense are formidable objections, and it does not act as a preservative of the 
iron of the boiler from corrosion. One government vessel, some time since, fitted with Hall's condenser, 
had no less than 22 miles of copper pipe for accomplishing the condensation of the steam. The use 
of salt water in boilers is attended with veiy little inconvenience if they be often blown out, and theh 
durability is little, if at all, increased by the employment of fresh water. 

Figs. 464 and 4G5 represent the boilers of the City of London steamer, a vessel lately con 
structed by Mr. Napier, of Glasgow, to ply between Aberdeen and London. These boilers are much 
upon the plan of the boilers of the Thames and Medway, and are fired from both ends instead of from 
one end, as in the boilers of the British Queen. There is a hanging water-bridge, it will be observed, 
at the end of the furnace, Fig. 464, beneath which the flame has to descend before it can enter the flues. 
This arrangement we look upon as very judicious. The hot air, by virtue of its specific levity, ascends 
into the upper part of the furnace-chamber, where it remains until it has given out a considerable por 
tion of its heat, and it is only after its specific gravity has been increased by the extraction of heat that 
it can overflow into the flues. It is also a good practice to place a hanging bridge of sheet-iron at the 
after-end of the flue, where it enters th i chimney. 

Figs. 466, 467, and 468, represent the original boilers of the steamer Tagus, constructed by Messrs. 
Scott, Sinclair & Co. The following are some of the dimensions of the original boilers : — Length 24 
feet 3 inches, height 10 feet ; breadth of each boiler 7 feet 6 inches, making the total breadth of the 
boilers about 22 feet 8 inches, with projections of rivet-heads. Length of under furnaces 8 feet ; length 
of upper furnaces 7 feet 6 inches. Breadth of furnaces 3 feet; total number of furnaces 12. Each 
boiler contains 14 iron pipes of about 10 inches in diameter, and 10 feet in length, through which the 
amoke passes on its way to the chimney. These pipes are formed of boiler-plate, with turned rings or 
collars attached to each end, which are inserted into holes in the smoke-box plates, and then rivetea 
over. These rivets are liable to get burned away by the action of the flame, as the collars within pre 



/O / ; C3\ o 

. ,/ 

fm • • o~\ 



yS : j 

Ci Q C2s 



D a O 

- - - - 24 feet. - A - A - A 
Scale.— 0-l38th inch = 1 foot. 
Transverse Section. 


Scale.— 9-128th inch = 1 foot. 

a. Horizontal Section through Furnaces. 

b. Horizontal Section above Furnaces. 

c. Horizontal Section above Tube** 


\\ (I 

^ A r\)\)\\)\)\) 

Hori?.v>rit!d Seciion. 

- - - 12 feet. - - - - 

SrALE.— 9-128(1) inch = I foot. 

Longitudinal Section. 


Scale.— - 075 inch = 1 foot. 
Perpendicular Section, 

%]r T% 

O o 

o c 


O o 

Longitudinal Section. 

Scale.— -075 incli = 1 foot 
itirough Flues. Uorizontal Section. Through Furnacea 

7 feet 6 in. 7 feet 6 in. 

Scale.— 9-128fh inch = 1 foot 

Transverse Section. Elevation. 



rents the water from getting across to the angle, and the plates into which they are fixed then get 
pressed ont by the force of the steam. It would he a good plan to cover these rivets with another 
perforated plate placed above them, the holes in which should be of a somewhat smaller diameter than 
that of the tubes. 

Fi"S. 469, 470, 471, 472, 473, and 474, represent the boilers of the Queen steamer, a river ves- 
sel, constructed by Messrs Rennie, and well known for her swiftness and efficiency. The object this boiler 


= i 

24 feet 3 inches. 

SciLE.— 9-128th inch = 1 foot. 

Horizontal Section. 

24 feet 3 inches. 

Scale.— 9-138th inch = l foot. 

Longitudinal Section. 

Scale.— 1.16th ir,ch = 1 foot. 
Transverse Section. Elevation. 


1 lolj 



1 1 



f 1! 

Scale.— l-16lh inch = 1 foot. 
Plan. Horizontal Section. 

Scale — 1-1 6th inch = 1 foot. 
Longitudinal Section. Elevation. 

seeks to attain is lightness, and it is therefore made so as to hold very 1 ittle water. It does not, howe7jr, 
appear to be well calculated to sustain any considerable pressure, though this is an object of importance 
in vessels intended to go fast. The following are some of the principal dimensions : — Length 13' S" ; 
breadth 12' 8" ; height 6' 0" ; length of furnaces 5' 2" ; length of tubes 5' 7" ; breadth of furnaces 
2' 8" ; diameter of tubes 2' 6" ; material of tubes brass. Total number of tubes 228. Diameter of 
cylinder of engines 29' 3'' ; length of stroke 4' 6". There are two engines on the direct action plan. 
Collective power 76 horses. 

If any considerable pressure of steam be employed in this boiler, it will be necessary to stay down the 
boiler top very firmly, both to the tops of the furnaces and the bottom of the boiler ; for the force act- 
ing against the boiler-top, and tending to raise it upwards, will be immense, if a high pressure be adopt- 
ed. To stay the boiler-top to the tops of the furnaces alone would not he sufficient, for the tops of the 
furnaces might alter their form, and the stays would then he of very little avail. The stays to the 
bottom of the boiler, however, if carried in the usual way, would have to be attached to the bottoms of 
the water spaces, and there they would be much in the way when the boilers are being cleaned. In- 
deed, it would be almost impossible to clean out the water legs effectually with stays so situated, and 
the best method, therefore, appears to he either to 
stay the boiler-top to a strong inverted arch spanning 
the water spaces, or to place a succession of iron 
arches over the furnace tops, to keep them in shape, 
after the fashion practised in Stephenson's locomo- 
tives, and to stay the boiler-top to these. 

Figs. 475 and 476 represent a small tubular 
boiler constructed by Messrs. Horton & Son for a 
coasting steamer called the Zephyr. This boiler 
has been found to perform well, and is, in every 
respect, satisfactory. The tubes are of iron, 3 
inches in diameter, and 6 feet long. Length of 
furnace, 6 feet ; number of tabes, 168. 2 engines. 
Consumption of coal per hour, about 6 cwt. The 
pressure of stt am is about 5 lbs. on the square 
mcn ; Scale— l-10th inch=l foot. Scale.— l-10th inch=l foot. 

Figs. 477 478, and 479, represent a boiler, byFront View and Transverse Section. Longitudinal Section, 
Messrs. Miller, Kavenhill & Co., of the tubular 




kind. It lias been found expedient to introduce a jet of steam into the chimney of this vessel to 
quicken the draught. The tubes are of brass, 3± inches in diameter, and the tube-plates are of iron. 
A galvanic action between the brass and the iron has been found to arise in some boilers, which 
shows itself, not at the ends of the tubes, but at the ends of the athwartship stays which bind the 
sides of the boilers together ; and the iron plate around these stays very soon acquires the appearance 
of having been scooped out by a knife ; but iu other boilers no action of this kind has been found 
to take place, and it has been doubted whether a leakage caused by the inadequate fastening of the 
stays has not had something to do with its production, The evil would probably be obviated by the 
application of a washer of zinc. Experience in the use of tubular boilers certainly shows that bra33 
tubes are on the whole the most eligible. Iron tubes are speedily eaten into holes by corrosion, and it 
is remarkable that the corrosion chiefly takes place upon the under side. Brass tubes, on the contrary, 
are found to last many years. It appears to be the best plan to refrain from attempts at scaling brass 
tubes, but they may be withdrawn once a year, cleaned, and reinserted. 

Figs. 480, 481, and 482, represent the boilers of the steam vessel Ocean. The tubes of these boilers 
are of iron, 3£ inches in diameter, and 9 feet long ; furnaces 7 feet long, and 2' 1" wide. There aie three 
boilers in all : the centre one with three furnaces, and the two wing ones with two furnaces each. Total 
breadth of boilers 19 A feet ; total length 14 feet ; total number of tubes, 378 ; two engines — diameter 
of cylinder, 56 inches ; length of stroke, 5A feet ; pressure of steam about 4A lbs. ; consumption of coal 
about 18 cwt per hour. Iu ordinary coasting vessels the plan of firing from each end is objectionable, 
as the length in the vessel occupied by an additional firing space is a manifest w r aste of room ; and 
there will be no difficulty in short voyages, about maintaining the trim of the ship on account of the 
stowage of so evanescent a cargo as coal in the wake of the furnaces. 

Scale.— 3-20th inch = 1 foot. 
Front View one-half in Section. 

Scale.— 3-20lh inch = 1 foot. 
Back View one-half in Section, 

- 11 feet. - 
Scale.— 3-20th inch = 1 foot. 
Perpendicular Section. 

Scale.— 3-28th inch = 1 foot. 
Longitudinal Section. 

Scale.— 3-28th inch = 1 foot. 

Horizontal Section through Tubes of Wing 

Boilers and Fujuaces of Centre Boiler. 

Scale.— 3-2Sth inch = 1 toofc 
Transverse Section. 



Figs. 4S3, 4S4, and 485, are different views of the boilers of the steamer Forth, belonging to 
the English Mail Steam-Packet Company. These boilers are well worthy of the attention of the 
engineer, as they have approved themselves more economical than any of the other boilers employed 
in those vessels, at the same time that there is an abundance of steam, and the speed of the vessel 
is well maintained. The following are some of the more important particulars : There are four 




r j / 


■ 7 / 

ll '\ 










: Y 





Scale.— 1-llth inch = 1 loot. 
Longitudinal Sections. 

Scale. — 1-llth. inch = 1 foot. 
Transverse Section. Front View. 


Scale— 1-llth inch = 1 foot. Scale.— 1-llth inch = 1 foot. 

Horizontal Section through Furnaces. Horizontal Section through Flues. Transverse Section. Elevation. 




! 1 




i t 

111 j 

=4i ; ; 

Scale.— 1-llth inch = 1 foot 
Horizon Section through Horizontal Section through 
Furnaces, Flues. 

Scale. — 1-llth inch ■=■ 1 foot. 
Transverse Sections. 



boilers, with three furnaces in each, making 12 furnaces in all Length of each boiler 13' C_" ; breadth, 
9' 10" • heisrht 14' 11'. There is a fore-and aft passage between the boilers, 2 feet wide and ar. 
athwart passage 18 inches wide. Length of furnace, T 4" ; breadth of furnace, 31f inches ; diameter 
of chimnev, 67 inches ; height of flues, 5 feet. . a . , 

Fi°-s 486 487 and 4S8 represent two sets of boilers constructed by Messrs. Bury, Curtis_ & 
Kennedy, for the two steam Vessels Wladimir and Der Greuss Adler, the one belonging to the Russian 
and Ibe other to the Prussian government, and both of the power of 320 horses: the boilers for the 
IWian vessel bein<- of the tubular variety, while those for the Prussian vessel are on the common flue 
plan. The shape and dimensions of the tubular boiler are shown in the figures by means of dotted 
Lea: and a just conception may thus be arrived at of the amount of space occupied by a tubular and a 
8ue boiler of* the same etBeacy in raising steam. 




|l — 




x 1- 


1 • 




Scale— 1-Sth inch = 1 foot. Scale.— 1-Stta inch = 1 foot 

a. Horizontal Section through Fimmces. a. Side View. 

b. Horizontal Section through Flues. b. LoDgitudinal Section. 

Figs. 489, 490, and 491, represent the boi- 
lers of the Retribution, a steamer of 800-horso 
power ; the engines being on the double cylinder 
plan of Messrs Maudslay. There is nothing very 
peculiar in these boilers, except their size ; in 
other respects they very much resemble the boi- 
lers of the Great Western, and of the Thames 
and Medway, also by Messrs. Maudslay & Field, 
of which we have already given delineations. 

Miscellaneous observations on the construction and 
proportion of hollers, and the accidents to which 

S~|| : I I , = , , , , they are liable. 

\ J[ J I J i ! J [ J [ J |_ < <^' The water-spaces. — The water-spaces between 

^ 1 I S*^ the furnaces should not be less than 5 to 6 inches 

ScALE.-1-Sih inch = 1 foot. Scale.- 1-Sth inch = 1 foot wid and between t]le flues 4 t0 5 ; nclies Tlle 
Transverse Section. Elevation bottom water _ spaoes should he g ; nclie5j f or the 

convenience of cleaning. It is usual to allow a space of 1 inch between the tubes of a tubular boiler, 
and these are best arranged in perpendicular rows, one over the other, by wjiich means the steam es- 
capes from their surface more, readily than when arranged zig-zag. When water-bridges are used, 
they should not be less than 10 to 12 inches wide, and their tops should incline about 3 inches to the 
foot, to allow of the steam escaping more readily from the interior surface. 

Heating surf ace arranged to permit the easy escape of the steam — Care must be taken, in proportioning 
the "boiler, that no part of the heating surface may be so situated that the steam will not readily escape 
from it to the surface of the water, as in such case the plate, being left in contact with steam in place 
of water, becomes intensely heated and destroyed, and an explosion is not an unfrequent result. It is 
found in practice that perpendicular heating surface, such as the sides of the rectangular flues in a flue 
boiler, is by no means so efficient for raising steam as an equal amount of horizontal surface, such as 
the tops of the same flues. The reason of this is sufficiently obvious ; as the steam, in the first case, 
rising perpendicularly from each portion of the surface of the metal, forms a film or stratum of vapor 
in contact with the sides of the flue, thus preventing the free access of the water to the hot metal ; but 
in the orbsr case, the steam, leaving the iron as soon as generated, allows the water to be constantly in 


contact with it. From the same cause, the flat bottom of an internal metal flu * is very inefficient a« 
heatino- surface ; and it is also found that plates which are liable to be exposed in this manner to 
imperfect contact with the water, either as side or bottom surface, are subject to a much quicker wear 
thau the tops of the flues of the same boilers. 

Strength of boilers. — 1st. To know the force which tends to hurst a cylindrical vessel crossways, or, 
in other words, to separate the head from the curved sides, we have only to consider the actual area of 
the head, and to multiply the units of surface by the number of units of force applied to each super- 
ficial unit. This will give the total divellc-nt force in that direction. 

2d. The amount of force which would tend to divide the cylinder in halves lengthways, by sepa- 
rating it along two lines on opposite sides, would he represented by multiplying the diameter by 
the force exerted on each unit &f surface, and this product by the length of the cylinder. But even 
without regarding the length, we may consider the force requisite to rupture a single band in the direc- 
tion now supposed, and of one lineal unit in breadth ; since it obviously makes no difference whether 
the cylinder be long or short, in respect to the ease or difficulty of separating the sides. The direllent 
force in this direction is truly represented by the diameter multiplied by the pressure per unit of sur- 
face. Hence, the thickness of the plates of cylindrical boilers should be in proportion to their diameters. 
Ordinary boiler-plates will not bear more than 23 tons to the square inch ; and as nearly one-third of 
the material is punched out for the reception of rivets, we must still further reduce the strength, and 
take 15 tons, or about 34,000 lbs. on the square inch, as the tenacity of the material, or the pressure at 
which a boiler would burst. 

Strength of the plates. — A practical limit is imposed to increasing the thickness of the plates of an iron 
boiler, by the defective conducting power of the material ; and it not unfrequently happens that boilers 
are weakened and destroyed by the very means adopted for securing additional strength, viz., by giving 
an injudicious thickness to those plates exposed to the greatest heat. 

It is now generally understood that if the plates of the furnaces are made thicker than about f of an 
inch, they are liable to be warped and " burnt" by the action of the flame, in consequence of the con- 
ducting power of the metal being insufficient to transmit the heat of the flame through the plate with 
such rapidity as to prevent the exposed side of the plate being softened and weakened by the intense 
heat, even although the other side of the plate may be in perfect contact with the water. From this 
cause, lapped joints, or rows of rivet-heads, should be avoided as much as possible iu parts of the boiler 
exposed to flame, which is much hotter than radiated heat. The best position for the joints of the plates 
in the fire-boxes is in a slanting line, just below the fire-bars, in the ash-pit ; and the plates for this 
part should be made as large as it is possible to have them rolled sound. 

The nsual thickness of iron plates for boilers is as follows : for fire-boxes, -| in. ; flues, sides and tops, 
!g- (the tops are sometimes ~ in.) ; bottoms, f , and sometimes ^ in. Outside shell of boiler, £ in. 
throughout, although the bottom is sometimes made yg- in. ; the up-takes to the bottom of the funnel 
should be ~ in. The tube plates in tubular boilers are made from ^ to £ in., charcoal iron. The funnel 
may be made with \ in. plate round the bottom, then T j in. and \ in. at the top. It should be divided 
by plates at the bottom, for 6 or 8 feet, into as many divisions as there are distinct boilers led into it. 

Construction of boilers. — The whole of the shells of boilers intended to withstand any considerable 
pressure, should be double riveted, with rivets 2| inches from centre to centre, the weakening effect of 
double riveting being much less than that of single riveting. The furnaces above the line of the bars 
should be of the very best plates, three-eighths thick, and each furnace above the bars should consist 
of three plates, one for the top and one for each side, the underseam of the side plates being beneath 
the level of the furnace-bars. The tube plates of tubular boilers should be also of the best iron, -| to 
1 iuch thick ; the shells jhould be of the best iron, and ^ thick, at the least. Angle iron should not 
be used in any part of a boiler, as in the manufacture it becomes reedy, like wire, and is apt t > split in 
the direction of its length. It is a much safer dependence to bend the plates, if it be carefully done, 
and without any more sharp turns than can be helped ; but it is convenient to use a little angle iron 
about the furnace mouths, which should be of the very first quality. The whole of the plates of 
boilers should be punched with a double punch, one nipple of which enters the hole last punched, while 
the other punches the hole ; and it is very convenient to have the puncbing-press provided with a 
travelling table, whereby the operation of punching and paring the .edges of the plates is made a self- 
acting one. The use of drifts and screw-jacks in putting the parts of boilers together should not be 
permitted. The rivets should be of the best iron, -J-^- in diameter. The whole of the work should be 
caulked both inside and outside, so far as it is accessible. It is very desirable that the space between 
the furnaces and tubes of tubular boilers should be sufficiently large to enable a man or boy to get in. 
The bend joining the top of the furnace at the after end with the bottom of the tube plate is very liable 
to get burnt away, and its repair will be most difficult, unless made accessible from the inside to hold 
on the rivets. 

Division of the boilers. — In the case of engines of large power it is preferable to divide the boilers into 
several distinct pieces, each complete in itself, and capable of being used either in conjunction with the 
others or separately. This affords facilities for examining, repairing, if necessary, and cleaning the 
boilers in succession. 

Staying and tubing of boilers. — It is usual to stay the flat portions of tubular boilers with about 1 \ 
inch round rods, from 16 to 18 inches apart each way, and flue boilers not quite so heavily. It is 
highly injurious to stay weak plates at long distances, as the alternate distension and contraction of the 
plate between tbe stays causes it to buckle round each stay every time that the pressure of steam ia 
added or removed. This action, in time, wears a furrow round the fastening of the stav by throwing 
off tbe scale from tbe surface cf the plate and opening the fibre of the iron, the circular piece of plata 
to which the stay-rod is attached remaining at the same time Quite sound 


By the English method, the tuhes of boilers are most generally secured at the ends hy means of ferulei 
driven tight into them, the holes in the end plates being usually countersunk, and a corresponding pro- 
jection being made on the ferules. The ferules next the furnace are best made of steel, while, for the 
other ends malleable-iron ferules answer as well. The tool in which the ferules are made consists of 
three pieces ; one piece is set in the anvil, and consists of a flat plate with a nipple on it, rising to half 
the depth of the ferule, and rounded at the corners ; the next piece consists of a ring furnished with a 
handle, and with its lower edge recessed slightly into the flat plate so as to steady it, and this ring is 
larger in its internal diameter than the nipple by twice the thickness of the ferule ; the last piece con- 
sists of another nipple made like the first, but formed with a head like a punch. A small hoop is 
formed by welding a piece of steel or iron, and is dropped into the space between the interior of the 
rin<* and the lower nipple ; the upper nipple is then forced down by striking the punch-head with a 
forne-hammer, whereby the ferule is moulded to the right form ; the parts are finally taken asunder, 
whereby the ferule is liberated. 

In brass tubes the use of ferules appears to be indispensable, but in the case of stout iron tubes they 
are unnecessary ; and the best plan, when iron tubes are used, appears to be to widen one end of the 
tube slightly, and to drive the tube in from the front of the boiler into both tube plates, the holes in 
the front plate being made one-sixteenth wider than those in the back plate, and the tube being 
widened correspondingly. Before the tubes are driven in, the holes in the tube plates must be slightly 
countersunk, and the tubes must finally be carefully riveted in. It will be expedient to screw a lew of 
the tubes into the tube plates instead of riveting them, so as to serve as stays, and also as abutments 
to rivet the rest of the tubes against. The screwed tubes should be left a little longer than the others ; 
and thin nuts made of boiler-plate should be screwed upon the projecting ends to prevent leakage, and 
add to the security of the staying. In fitting in the tubes in this way, great care is necessary to make 
them perfectly tight; and it will be expedient to turn the ends slightly in the lathe to give them a 
trifling taper, and make them all precisely of the same size. Iu driving them in, each tube should not 
be driven home at once, as that will spring out the iron between the holes ; but they should be all 
fitted in first with the common chipping hammer, and when thus all equally fitted, they should be 
driven home by a heavy hammer, or ram. The countersink in the holes must be but slight, and must 
be filled rather by riveting up endways than by riveting over. Iu some cases boilers are made with 
collars riveted on the tubes immediately behind, the tube plates, but this plan is attended with the 
objection that a tube cannot be renewed without taking the boiler asunder; and with the still greater 
defect, as it appears to us, that the ends of the tubes will be liable to get burned away in consequence 
of the internal collar preventing the access of the water. Boilers formed on this plan, therefore, will, 
we believe, be found to become leaky at the ends of the tubes ; and unless stayed, independently of the 
tubes, the tube plates will be forced asunder by the pressure of the steam. 

Galvanic Action. It is very necessary, however, in designing marine engines and boilers, to guard 
against the destructive effects of galvanic action in all cases where two metals of different degrees of 
solubility in salt water (such as iron and brass) are placed in juxtaposition ; when the iron, being the 
most oxidable metal, suffers a rapid corrosion. To prevent this action, as well as for economy, it is 
now usual to furnish marine boilers with iron tubes in place of brass, from 2^ to 3^- inches external 
diameter, and about A to -J- inch thick. 

Clothing of boilers. Although it must be allowed that in all cases the clothing of marine boilers with 
non-conducting substances, such as hair-felt, wood, &c, is highly advantageous for the production of 
steam, yet this practice is alleged in some instances to have induced a rapid wear in the plates of the 
boiler. This unlooked-for result is most apparent in boilers 'wliieh are frequently used and disused alter- 
nately, the corrosion taking place on the interior surface. The conjecture as to its cause is, that owing 
to the alternate wetting and drying of the plates of the clothed boiler, the rust may be more apt to 
scale off, and thus constantly present a clean surface for corrosion, this action recurring each time that 
the water is blown out of the boiler ; but when, on the other hand, the boiler is naked, the internal 
surface never thoroughly dries, owing to the evaporation being checked by the low temperature, and 
the saturation of the confined air. The clothing of marine boilers which make long voyages is never 
attended with these injurious results, nor are they ever experienced in land boilers. 

Beaavng of boilers. The manner of bedding marine boilers is a point of much importance, and 
will materially affect the durability of the bottom plates. A good practice, iu the English service as 
well as in our own, is to form a close platform of 2-inch fir deals over the keelsons, upon which the 
boiler is then bedded with a cement or mastic of lime and drying oil, laid about 1 inch thick over the 
timber. This sets quite hard, and pi events the bilge-water (which in wooden ships is highly acid) from 
washing up to and corroding the plates of the bottom. The cement is also intended to stop any leaks 
which may break out in the bottom of the boiler, as well as to strengthen it in the event of a rapid 
corrosion taking place inside. Unfortunately, a perfectly close contact cannot be maintained between 
the iron and the cement, from the unequal degree of expansion of the two materials by heat, so that 
the effect of a leak in the bottom plates is frequently that the brine extends itself for a large space be- 
tween the two surfaces, and the wear of the boiler is increased instead of diminished. The best practice 
is, perhaps, that of resting the boiler on saddles of cast iron fixed on the boiler bearers, which leaves 
ihe bottom exposed for examination, painting, and small repairs if necessary, the bottom of the vessel 
under the boilers being at the same time kept clean and dry by the bilge-pumps. 

Duration of iron boilers. As will be easily understood from the preceding remarks, the duration of 
an iron boiler varies according to the treatment it has received, and the facilities afforded by its con- 
struction for thoroughly examining, cleaning, and repairing the parts. Thus, while some have been 
worn out with three years' service, others of the same thickness of plate have lasted six and eight years. 
A government steamer is seldom in commission longer than three years at one time, and at the end of 
this period the boilers very frequently require renewal ; or if they' are not much worn, and if the vessel 


be of such a class that she will probably not be seiit on foreign service, the boilers are repaired and 
made to serve another two, or it may be, four years. 

Miscellaneous remarks about boilers. All the rough nuts about a steam vessel which require to be 
screwed and unscrewed frequently, such as the bolts of the man-hole and mud-hole doors of the boiler, 
should have large square nuts, and the bolts should be strong and have coarse threads. Hexagonal nuta 
speedily become round in the hands of the firemen, by whom the mud-hole and man-hole doors are gen- 
erally taken 01% and fine threads soon get stripped and overrun. It is much the safest way to put on 
both mud-hole and man-hole doors from the inside, with cross-bars on the outside to keep them closed. 
The plan sometimes followed of putting on mud-hole doors from the outside, and securing them by one 
or two bolts, is a practice to be reprehended as full of danger, as, if the thread strips or the bolt breaks, 
the door will fly off, and the boiling water rush out, scalding every one in the vicinity. Mud-hole doors 
of this kind, even if they leak, cannot be screwed up to tighten them when the steam is up, as there ia 
a perpetual risk, in tightening the doors, of stripping the thread or breaking the bolt. 

The tops and steam-chests of boilers, and the bottoms of the ash-pits, are the first parts to give way. 
The steam-chest wears chiefly from internal action ; in some cases the iron exfoliates in the tbrm of a 
black oxide, which separates in flakes like the leaves of a book ; while in other cases the iron is, as it 
were, gouged away, and the heads of the rivets are worn off as if by an acid. It is most important 
that a remedy should be found for this evil. The ash-pits are worn away chiefly by the wetting of the 
ashes in the stoke-hole, and it is expedient to apply shield-plates to those places when the boilers are 
made, which plates only will be exposed to wear, and may be easily renewed, leaving the ash-pits uu - 
touched. The best method of setting boilers appears to be to set them on a platform, and care must be 
taken that no projecting copper bolts touch the boilers in any part, as they will be very likely to corrode 
the points of contact into holes. The platform may consist of 3-inch planking, laid across the keelsons, 
nailed with iron nails, and caulked and puttied like a deck. The surface may then be painted over with 
thin putty, and fore and aft boards of about half the thickness may then be laid down, the heads of the 
nails being well punched down. This platform must next be covered with mastic cement, and the 
cement must be caulked beneath the boiler by means of wooden caulking tools, so as completely to fill 
every vacuity. Coomings of wood must next be laid round the boiler, to confine the cement ; and the 
space between the cement and the boiler must be caulked full of cement and be smoothed off with a 
slope to shed the water. 

The large rivets sometimes used as stays for the shells of boilers, are objectionable, as the heads very 
often come off, and if the fracture be between the boilers in a position not accessible from the outside, 
it will be necessary to empty the faulty boiler of its water, in order to repair the defect. The 
sides of furnaces should always be made to incline to each other, so that the crown is not so 
wide as the fire-bars, and it is a good arrangement to place the bars adjoining the sides close against 
the sides throughout their length, so as to leave no air-space in that situation. By this arrangement, 
the intensity of the heat acting immediately against the plates of the sides is diminished. A crack in a plate 
is most conveniently closed by boring several holes along its length, and closing them with rivets having 
large heads, which cover over the defects. If a patch be applied to the top of a furnace or flue, it is 
better to apply it from the inside of the boiler rather than from the flue, as in the latter case a recess 
is left into which deposit falls, and a hole is likely then to be burnt again in the same place. If the 
furnace mouth be contracted by bending in the sides of the furnace, as is the general practice, it is 
necessary to be very careful that scale does not accumulate in these corners, else they will be very 
liable to be burnt into holes. 

Respecting fire-bridges, the preferable practice, on the whole, appears to be to constnict them of 
brick, rather than to make them water bridges, as with water bridges there is often trouble from the 
cracking of the plates. If water bridges, however, be used, they should be made with a great inclina- 
tion in the breadth of the furnace, to facilitate the escape of the steam. Flame-bridges have been 
introduced into the furnace flues of steam vessels on some occasions, consisting of a pile of fire-brick, 
between which and the sides of the flue only a space of about three inches is left for the flame and 
smoke to pass through, and the flame is spread in a sheet over the interior of the flue. Where the flue 
is very large, the use of a flame-bridge appears to be expedient, and in land boilers with large internal 
tubes, its use has been attended with beneficial results ; but in the majority of marine boilers, we be- 
lieve that it will prove of but little sex-vice. 

Explosion. Host explosions are found to arise either from undue pressure of the steam, or from the 
overheating of the plates composing the boiler. The plates of the boiler may become overheated 
either in consequence of a want of water in the boiler, or from such a configuration of the internal 
parts of the boiler that the steam when formed cannot escape freely to the surface. The bottoms of 
large flues tipon which the flame beats down are very liable to injury from this cause ; and the iron in 
such a case will probably be softened by the heat, and in all probability will collapse upwards. 

The plugs of fusible metal sometimes introduced into boilers to obviate explosions by melting out 
before the steam can reach any high temperature, are found in practice to be of little avail. The 
compound metal is not homogeneous, and the more fusible of the metals is melted first, and is forced 
by the pressure of the steam out of the interstices of the less fusible metal, leaving its place to be 
supplied b} r the debris which all water supplies. The consequence is that the plug ceases to be fusible 
metal of the kind originally introduced, and cannot be melted by the steam even at a pressure and 
temperature much above that fixed as the requisite fusing point. In tubular boilers, however, it is a 
good plan to introduce lead plugs in the tops of the fireboxes* — not with the idea that they will be melt- 
ed by the steam where its pressure gets high, but to be melted out, and give notice of danger, should 
the water fall too low. 

Every boiler should be furnished with a steam-gauge, which may give indication of danger should 
the pressure become too great, and the passages leading to the safety-valves should have no connection 


•with the pipes leading to the stop-valves. In some cases stop-valves have been lifted from their seats 
and forced into the mouth of the pipe, so that no steam could escape thereby ; and in consequence of 
the safety-valve pipe springing from the pipe connecting the boilers, the boiler thus blocked up was in 
■Teat danger of bursting, and would have burst if the fires had not been immediately drawn. In the 
case of any derangement of the safety-valve, or of the cone in the waste steam-pipe of a steam vessel 
getting loose, and blocking up the mouth of the pipe, the pressure in the boiler may be eased by open- 
mo- the blow-through valves of the engines, and the steam-gauge will in all cases tell whether any 
undue pressure exists. See Gauge. _ _ _ 

Extract from a report made by the Association in Manchester, for preventing steam boiler explosions, 
and for effectmo- economy in the raising and use of steam : " The chief inspector has reported several 
cases of imperfection tending to accidents, and, in particular, has found many flues so constructed as to 
transmit heat directly to the steam in the boiler, not only when the water is deficient, hut when at its 
daily working level, thus surcharging the steam with heat, and endowing it with, one essential element 
of explosive power, which may he instantly developed by the admixture of water, by agitation or other- 
wise. The fact that steam, in contact with water in a quiescent state, may be heated to 500 = or up- 
wards, without any corresponding effect on the steam gauge, or proportionate increase of pressure, 
appears to he established on good authority. But the precise condition under which the surplus heat 
thus accumulated in the steam may combine with water to produce explosion, is not fully known. 

" Our attention has been directed — 1. To an examination of all boilers placed under our inspection, 
with a view to ascertain, as correctly as possible, their actual condition, and whether they were adapted 
to their ordinary working pressure ; also, whether they were provided -with the requisite mountings, 
and if the same were kept in good working order. — 2. In those cases of explosions which have taken 
place in the neighborhood, to an investigation of the peculiar circumstances connected therewith, in 
order, if possible, to ascertain the real cause, and the best means of preventing the recurrence of such 
accidents. — 3. To ascertain by comparison the most advantageous construction, dimensions, and work- 
in" of boilers in regard to safety, economy of fuel, and durability. — 4. To ascertain the most economi- 
cal system of employing steam as a motive power. 

" The number and description of boilers at present under our inspection are as follows, viz. : — 

Pressure per square inch. 

31 lb 46 ft, 61 ft, 

to 45. to 60. to 75. 

. 144 . 60 . 28 

10 . 6 . 7 

48 , 12 . — 

31 . 32 . 2 


15ft, or 

16 ft, 

Cylindrical, with internal 


to 30. 



Cylindrical, without do. . 

. 10 . 


Galloway's patent boilers 
Multitubular " 

. 12 . 


Butterley " 
TV agon " 

. 43 . 

. 38 . 



76 ft 


to 80. 













Total 1SS 350 234 110 37 1 920 

Of the above, 81, or nearly nine per cent., have been found to he in a dangerous state, from the follow- 
ing causes, viz. : — 

Construction or strength not adapted to the working pressure . . . . . 24 

Defects in the plates or angle iron .... ... 9 

Defects in the boiler mountings .... ... 26 

Injury sustained from deficiency of water . ... 19 

Ditto " deposit of scale . ... 3 

Total ... 81 

In addition to the above 19, rendered dangerous from deficiency of water, there are 14 others which 
have been injured to a less extent from the same cause. This is evidently the most frequent cause of 
explosion, as will be explained hereafter ; and as it is important to provide such means of prevention 
as will be effective in cases of negligence on the part of the fireman, we would suggest, first, the general 
adoption of open stand-pipes, where applicable, or safety valves, in connection with a float, to allow the 
escape of steam, whenever the water falls below the fixed limit. — 2. The use of fusible metal plugs, 
fixed on the top of the flues above the fire. These should stand sufficiently high to melt before any 
part of the flues could be uncovered with water. The usual practice of inserting a lead rivet or plug in 
one of the plates is worse than useless, inasmuch as owing to the inclination usually given in setting 
boilers, a considerable portion of the flue must be exposed, and may even become red-hot, before such 
lead plug can be melted ; under which circumstances an explosion is the probable consequence. 

"Although the possibility of surcharging steam, while in contact with water, is still disputed by 
many engineers in this country, this question was satisfactorily solved by a committee of the Franklin 
Institute, in America, above twenty years ago. In the report of this committee, it is stated that ' the 
temperature was carried to 533 degrees Faht., when the pressure, shown by the gauge, was 6'82 at- 
mospheres : while saturated steam, at that temperature, would have had a pressure of more than 60 
atmospheres ;' and further, ' these experiments, which lasted more than two hours, show that the sur- 
charged steam remained in contact with water without acquiring from it the water necessary to con- 
vert it into saturated steam, but retaining its surcharged state.' Several instances which have come 
under our own observation might be adduced in confirmation of the experiments of these gentlemen, 
but we shall only mention one, which lately occurred, as sufficient for our present purpose. The boilei 


referred to, contained two internal furnaces, uniting in one flue, find had been filled with water to the 
usual height by a pipe leading from a reservoir. The end of this pipe was about 9 inches below the 
top of the furnaces. About two hours after lighting the fires, the steam (being at 8 lb, as indicated by 
the gauge) was turned into the mill for the purpose of warming it. Shortly after this the attendant 
observed that the water had disappeared from the gauge glass, and was forced back into the reservoir, 
the valve on the feed-pipe not having been entirely closed. At this time the upper part of the furnaces, 
above the surface of the water, had become red-hot, and the temperature of the steam was such that a 
block of wood, resting on the top of the boiler, was converted into black charcoal, and yet the pressure 
never exceeded 8ft>. The communication with the reservoir having been closed, the fire doors opened, 
and the damper shut, the boiler was allowed gradually to cool ; and although the tops of the furnaces 
were depressed, no explosion took place. From this it is evident that steam may be raised to a high 
temperature, while in contact with water, and yet remain at a low pressure. And this condition can 
only arise from a deficiency of water in such steam ; we may reasonably infer, that if this could by 
any means be supplied, we should have an almost instantaneous increase of density and pressure pro- 
portionate to the degree of saturation. This will fully account for the difference in intensity of many 
explosions, and why these should so frequently occur immediately after starting the engine, admitting 
water into the boiler, or lifting the safety valve, all of which tend to produce agitation of the water, 
and to promote its diffusion amongst the steam. Although this theory of boiler explosions, which vras 
advauced by the late Mr. Perkins many years ago, has not hitherto been generally admitted, certainly 
the facts which have come under our own observation seem fully to confirm its accuracy. The two 
last subjects which have been proposed for investigation require a greater amount of data than we have 
as yet been able to obtain ; and although we have had occasion to remark great errors in many of the 
present modes of employing high-pressure steam, we should not now be justified in expressing a decided 
opinion as to which system is positively the best, nor which is the best construction of boiler. . In con- 
nection with the working of boilers, the subject of smoke-prevention has not been overlooked. Our 
experience ou this subject tends to the conclusion, that without much difficulty or expense the smoke 
nuisance may be greatly abated, in almost every description of boiler, and that this will be accompanied 
by a saving of fuel, provided such attention as might reasonably be expected be given by the fireman." 

* Explosions from Incrustations. — A boiler bottom getting red hot is not likely to take place gradually 
while the engine is at work, the water-feeding apparatus in order, and the boiler kept clean. But if a 
boiler is allowed to become dirty, or covered with indurated or incrusted earthy matter, interposed be- 
tween the iron and the water, there is then no difficulty in accounting for such circumstances producing 
an explosion at any time; -and the way in which it operates towards that end appears to be something 
like the following : 

It is known that an internal coating of incrustation, or boiler scale, is liable to crack and separate 
into large pieces, which are thrown ofFfrom the boiler bottom at some particular degree of temperature, 
depending upon the thickness of the scale and the kind of substance of which it is formed. We can 
easily suppose that by a little hard firing, and unduly heating the boiler, a large portion of scale may 
be suddenly detached, uncovering a considerable area at a temperature something exceeding the 
maximum evapora&nff point, which is well known to be considerably under the lowest red heat of iron. 
Now, the first effect produced will evidently be a certain amount of repulsion between the overheated 
iron and the water, which may continue for several seconds, and perhaps for a few minutes ; this may 
account for the sudden decrease in the supply of steam that has sometimes been observed just before the 
explosion of a boiler has taken place. There must also be a gradual diminution of temperature during 
this short space of time, in that part of the overheated iron which is exposed to the water — creating a 
contraction of the metal — increasing as the decreasing temperature of the iron approaches the maximum 
evaporating point, which is at about 350° to 400" Fahrenheit, and causing a corresponding strain on 
the rivets in the boiler bottom. The direction of this strain may generally be traced on examining the 
bottom plates of any old boiler, and will be found to radiate in Hues proceeding from the part which 
has been most acted on by the fire. 

The next and concluding step, in case of the metal not being able to withstand the strain caused by 
its own contraction, will either he a sudden crack or fracture in some direction across this exposed 
part, or, what most generally happens when an explosion results, the sudden giving way of some bad 
seam of rivets, which the most nearly coincides or is parallel with the direction of what would otherwise 
be the true line of fracture. This may possibly be at some distance from the part which has been 
overheated, thereby giving the increased effect of great leverage to the pressure acting upon all that 
portion of the boiler included between the overheated part and the actual line of fracture. Now the 
consequence is, not perhaps that this portion is blown out, as would most probably be the case with 
very bad iron, but it will be bent or doubled back, the line of flexure running across the hottest or the 
weakest part of the iron. This may help to account for the remarkable way in which we sometimes 
find exploded boilers twisted and doubled up. A rupture being thus effected, an explosion is inevitable, 
if the hole be sufficiently large. 

"When an incrusted boiler bottom becomes highly heated, and the water at the same time too low, it 
very commonly happens that a large quantity of water is immediately let in, when the consequences 
are similar to those just described : for the internal coating of scale being suddenly contracted by the 
cooling effect of the water admitted, it is detached in the same manner as it would have been by the 
expansion of the iron, and the same effects produced, although perhaps more speedily, as the water 
admitted will reduce the temperature of the exposed part of the boiler bottom more rapidly to the 
maximum evaporating point. 

Whenever a boiler bottom is seen, or supposed to be, approaching to redness — and that can onlv 

* Armstroog on steam boilers, 1856. 



happen when the water is not boiling, or when the engine is standing — the engine-man should be cau- 
tioned ao-ainst allowing a fresh supply of water to go into the boiler, whether the boiler is short of 
water or not, until after the engine has been some time at work. My advice to engine-men in such 
cases is not to start the engine at all, but to open the fire-doors and stand at a safe distance until all 
goes cool. I would not have him stop to pull the fires out, and on no account to open the safety valve, 
as being little less hazardous than starting the engine. If, indeed, he knows the safety valve to be 
overloaded or made fast, and the steam still continues to rise with the fire-doors open, the fires may 
then be quenched by a jet of water from a hose pipe, or other safe means. 

Deposit of Sediment. — All natural waters hold various solid matters in solution or suspension ; when 
in the latter state they admit of being removed by filtration; but no system of filtration, on a scale 
sufficiently large to supply a moderate-sized steam engine at a light expense, has yet come into prac- 
tical use. However, it occurred to a gentleman several years ago to hit upon a very simple and effectual 
substitute. And that was, instead of separating the water from the dirt, before passing it into the 
boiler, he separates and collects the dirt from the water, after it is in the boiler, by means of a series of 
vessels, shelves, or trays, placed up and down the boiler, constituting, in fact, so many portions of what 
collectively might be considered a substitute for a false bottom, upon or into which all the matters held 
in suspension are deposited. This, in fact, is the whole of the principle of Sir. Anthony Scott's patent 
of 1827, which has been so frequently re-patented and re-registered since that time, like many bad 
copies of good pictures, some of them so very bad that the patentee, if he were living, would not know 
that they were even meant for imitations. 

These sediment vessels operate much after the same manner as certain quiet still places do along the 
banks of rivers, in causing sand or mud to accumulate in them ; making so many places of shelter, 
where any movable matters being accidentally deposited, they remain free from agitation and not dis- 
posed to move out. In a boiler containing boiling water, of course the same principle prevails ; the 
steam rising from the boiler bottom — the sole cause of ebullition in all cases— being the agitating agent. 
In fact the water never boils within the internal vessel or sediment receiver, however violently it may 
boil externally; and the more violently the water boils the more rapidly the internal vessel collects all 
loose sediment floating about in the water. Excepting for calcareous incrustations, the process was 
perfectly successful in keeping a boiler clean. The only difficulty in its practical application was liability 
to neglect in cleaning out the collectors themselves when they got filled with deposit, and the necessity 
of emptying the boiler for that purpose. 

For the above, reasons it appeared desirable to the patentee to have his cleansing apparatus made 
self-acting, that is, to chan itself out, without interruption to the working of the engine, or letting 
down the steam ; which improvement R. Armstrong effected in 1829, when the first complete boiler- 
cleansing machine was executed and applied to a boiler at the calico-printing works of Messrs. Thomas 
Marsland and Son, in Stockport, who afterwards had fifteen boilers so fitted. Since the above period 
they have continued in general use in Lancashire. 

The general form of this apparatus is shown by fig. 492. Many hundreds have been made and 
adapted to various kinds of boilers, including those of railway locomotives and steamboats. In thf 


ccale.— Jth inch = 1 foot. 
Longitudinal Section and Elevation of Collectors. 

the narrow collecting apertures adjusted partly above and partly below the surface of the water I 
ibis way it is used by opening the valve at the end of the boiler, and putting the handle of the aoitatoi 
in motion for half a minute, by which the contents of the receiver at the bottom of the boiler are dis- 


charged upwards through the pipe on the right hand. This operation creates a current, which draws all 
the scum and froth that cause the priming, from all parts of the water surface into the collecting vessel 
and down into the receiver, whence they are discharged to the outside of the boiler by a repetition of 
the process. 

By thus slimming the dirt from the top of the water, clean dry steam is supplied to the cylinder of an 
cno-ine instead of a mixture of steam and dirty water, causing, in ordinary cases, such great waste of 
power by friction on the piston and piston-rod, and unnecessary consumption of tallow. 

Great consumption of lubricating material is always proof of imperfection in machinery. Instances 
are not wanting of large stationary engines working for months together without grease of any kind to 
the piston-rod, contrasting greatly with the lavish use of that material in marine engines, rendered 
necessary mainly by the greater liability to prime. The old device of throwing tallow into a steam- 
boat boiler, in order to prevent priming, is still without a satisfactory theory. The only suggestion tc 
account for it worth attention, is one by Mr. TV. Keld Whytehead, C. E., in an article on the priming 
of boilers, in the " Artizan Journal" for December, 18-18, in which he supposes that, as the tallow re- 
quires a very high temperature to vaporise it, it " consequently floats like a hot plate on the surface of 
the water, and tends to separate the particles of water from the steam as they rise." 

Calcareous Incrustations.— When the incrustation forming on the inside of boilers consists principally 
of argillaceous or silicious matters, it is easily prevented by the use of one or the other of the above 
described apparatus. "When, however, any considerable proportion is either carbonate or sulphate of lime, 
considerable difficulty is experienced in preventing its formation to an injurious extent. The latter sub- 
stance more especially, it is well known, has withstood all attempts at complete prevention by chemical 
means, except such as would be also injurious to the iron. The principal remedial agent that has been 
found beneficial in any degree to mitigate the effects of this substance, is crushed potato, which does not 
act chemically, hut mechanically, the pulp of the potato being supposed to envelope the crystals of the 
sulphate of lime as they form, and prevent their adhesion to each other. 

With respect to the incrustations of carbonate of lime, the case is very different. It admits of 
various methods of preventing its formation by chemical reagents. The most popular of the patent 
remedies is that of Dr. Eitterbandt. This plan is to put into the boiler daily a small quantity of mu- 
riate of ammonia, or sal-ammoniac, the effect of which is, that any bi-carbonate of lime in solution in 
the water is decomposed, the muriatic acid of the muriate of ammonia taking the lime and keeping it 
in solution, while the carbonic acid joins the ammonia, forming carbonate of ammonia, which passes off 
along with the steam. It need not be observed that this remedy can have no effect whatever in pre- 
venting the sulphate of lime incrustation. 

The theory of the following remedy is something like the reverse of the foregoing. It is to put into 
the boiler daily or weekly a quantity of quick or newly-slacked lime, the effect of which is to convert 
the soluble bi-carbonate into the insoluble carbonate of lime, which, instead of being kept in solution as 
muriate of lime is in Dr. Bitterbandt's remedy, is precipitated and collected without any trouble by 
sediment collectors, or collected and discharged from the boiler by the cleansing machine. This puttin" 
in of lime to take out lime is a nice application of Dr. Clark's simple and efficacious method for purify- 
ing water on a large scale, now so well known and generally approved by water-works companies. 

In Lancashire, where generally a great portion of the boiler scale is sulphate of lime, it has long 
been a practice to use ox-feet, or any animal substance convertible into jelly by boiling, with good effect. 
Bnt they are liable to promote priming, and", like potatoes, they require frequent renewal. One Eng- 
lish patent, now expired, specified the use of all kinds of vegetable matter or extract without exception, 
preferring that which gives out the greatest quantity of coloring matter, as logwood, bark, or tan. Also 
turf, peat, manure, leaves, saw-dust, and charcoal. Other patentees recommend urine, glue, blood, 
dung, and night-soil. Also sugar, starch, treacle, flour, malt, and the bottoms or settlings of beer 
barrels Most of the above articles may be used with advantage where there is not much of the sul- 
phate, but they all act mechanically. Tan and salt are the principal ingredients in some of the best of 
the foreign patents, which generally also contain some corrosive materials that are difficult to particular- 
ise and hazardous to use. 

Incrustation. — The incrustation of boilers by saline deposits was a much mora important subject at 
one time than it is now, as nothing has been more clearly established, of late years, than that boilers 
may be preserved effectually from any injurious incrustation by abundant blowing off. Brine-pumps 
arenow in extensive use for withdrawing a certain quantity of water at every stroke of the engine ; 
end the water so withdrawn has to pass through or among pipes carrying the feed-water to the boiler, 
60 that some interchange of heat is there effected. These refrigerators, however, as they are grotesquely 
called, are in some respects had things : the quantity of heat they save is, we believe, inappreciable ; 
and the small pipes of which they are built up are liable to get choked, thereby endangering the boiler 
by the unconscious concentration of its contents. To guard against this danger, every engine fitted with 
brine-pumps should be provided with an hydrometer for telling the specific gravity of the water in the 
boiler, so that the engineer may not be cheated by the defective action of the pumps, or suppose that 
they are operating when they are really inert. In the case of blowing out a boiler in the usual way, 
the engineer looks at his glass gauge-tube, and keeps the blow-off cock open until the water-level has 
descended through the required distance, so that, under these circumstances, no doubt can arise that the 
boiler has been emptied of a certain quantity of water; but there is no such assurance in the case of 
the continuous extraction of the water, either by brine-pumps or by a continuous blow-off; and all 
boilers using either of these expedients should be fitted with hydrometer gouges as a precaution against 
the contents of the boiler being suffered to reach au injurious concentration. The prevailing fault 
among engineers, however, is that they do not blow off enough, the idea probably being that a consid- 
erable check is given to the generation of the steam by the introduction of colder water in lieu of th« 
water abstracted; but the waste of heat by effectual blowing off is very inconsiderable — much less, u> 


deed, than is occasioned by the difficulty of getting steam from brine, or of transmitting heat to tha 
water through flues covered with incrustation, much of which heat, in consequence, ascends the chim- 
ney. There is no gain, therefore, in any respect, by penuriousness in blowing off; and there is much 
injury to the boiler, for incrusted plates become overheated ; they blister, crack, and get burned out, 
and make expensive repairs indispensable. Proprietors of engines should accept of 710 excuse for tho 
accumulation of salt or incrustation within their boilers; for such deposits arise altogether from insuf- 
ficient blowing off. 

The best method of scaling boilers appears to be by lighting a train of shavings in the furnaces and 
flues after the boilers have been emptied of water. The rapid expansion of the metal thus occasioned, 
causes the scale to crack off; and, if the flues be then washed down with a hose, the scale will fall to the 
bottom of the boiler, and will issue out with the water on taking off the mud-hole doors. This plan 0! 
sealinf, however, is one that the engineer must execute himself, and must not intrust to firemen or othei 
subordinates, as the metal of the boiler might be damaged if the heat were made too great. The safety- 
valve should, obviously, be kept open while the boiler is being heated and cooled, to obviate any pres- 
sure or exhaustion within it. This plan of scaling, however, will seldom be necessary if due attention 
be paid to blowing off by the engineer ; and if the quantity of scale be inconsiderable, or partial in its 
attachment, the best plan will be to chip it off with a hatchet-faced hammer, and then wash down the 
flues with the hose, as before described. 

Corrosion. — The corrosion of boilers is one of the most obscure subjects in the whole range of engi- 
neering. Marine boilers seldom last more than four or five years, whereas land boilers, made of the 
same quality of iron, often last eighteen or twenty years ; yet the difference in durability is not the 
effect of any chemical action upon the iron by the contact of sea-water, for the flues of marine boilers 
rarely show any deterioration from this cause, and, even in worn-out marine boilers, the hammer-marks 
on the flues are as conspicuous as at the time of their formation. The thin film of scale spread over 
the internal parts of the boiler would, of itself, preserve that part of the iron from corrosion which is 
situated below the water-level; but, whatever be the cause, it is a rare tiling to find any internal cor- 
rosion of a boiler using salt water in those parts of the boiler with which the water comes in contact. 
The cause, therefore, of the rapid wearing out of marine boilers is not traceable to the chemical action 
of salt water, and steamers provided with Hall's condensers, which supply the boilers with fresh wa- 
ter, have not reaped much benefit in the durability of their boilers. The operation of the steam in 
corroding the interior of the boiler is most capricious — the parts which are most rapidly worn away 
in one boiler being untouched in another, and in some cases one side of a steam-chest will be very 
much wasted away while the opposite side remains uninjured. Sometimes the iron exfoliates in the 
shape of a black oxide which comes away in flakes like the leaves of a book, while in other cases the 
iron appears as if eaten away by a strong acid which had a solvent, action upon it. The application of 
felt to the outside of a boiler, has in several cases been found to accelerate sensibly its internal corro- 
™»n. Boilers in which there is a large accumulation of scale appear to be more corroded than where 
thsre is no such deposite, and where the funnel passes through the steam-chest the iron of the steam- 
chest is invariably much more corroded than where the funnel does not pass through it. These facts 
appear to indicate that the internal corrosion of marine boilers is attributable chiefly to the existence of 
surcharged steam within them, which is steam to which an additional quantity of heat has been com- 
municated subsequently to its generation, so that its temperature is greater than is due to its elastic 
force; and on this hypothesis the observed facts relative fo corrosion become easily, explicable. Felt 
applied to the outside of a boiler may accelerate its internal corrosion by keeping the steam in a sur- 
charged state, when by the dispersion of a part of the heat it would cease to be in that state. Boilers 
'n which there is a large accumulation of scale must have worked with the water very salt, which 
necessarily produces surcharged steam ; for the temperature of steam cannot be less than that of the 
water from which it is generated, and inasmuch as the boiling point of water, under any given pressure, 
rises with the saltness of the water, the temperature of the steam must rise with the saltness of the 
water, the pressure remaining the same ; or in other words the steam must have a higher temperature 
than is due to its elastic force, or be in the state of surcharged steam. The circumstance of the chim- 
ney-flue passing through the steam will manifestly surcharge the steam with heat, so that all the cir- 
cumstances which are lonnd to accelerate corrosion are, it appears, such as would also induce the 
formation of surcharged steam. Besides, the natural effect of surcharged steam is to oxidate the iron 
with which it is in contact, as is illustrated by the familiar process for making hydrogen gas by sending 
steam through a^ red-hot tube filled with pieces of iron ; and although the action of the surcharged 
steam in a boiler is necessarily very much weaker than where the iron is red-hot, it manifestly must 
have some oxidizing effect, and the amount of corrosion produced may be verv material where the 
action is perpetual. Boilers with a large extent of heatiug-surface, or with descending flues circulating 
through the cooler water in the bottom of the boiler before ascending the chimney, will be less corroded 
internally than boilers in which a large quantity of the heat passes away in the smoke. If these views 
be correct, then to prevent the internal corrosion of marine boilers it is onlv necessary to take care that 
the water in the boiler shall bo as fresh as possible, and that the root of the chimney ska.' either ba 
lined with fire-brick, or not go through the steam at all. 

Pruning is the tendency of the water in the boiler to foam and pass in a state of spray into the cylin- 
der along with the steam, and when in too great a quantity to escape through the steam port in tho 
return stroke, it infallibly breaks down the engine. This effect must invanably follow the priming 
of a sufficient quantity of water in the cylinder of a beam engine in a factory, because it is not and can- 
not be expected to be calculated to withstand a sudden Mow, and such it is in reality. For if the water 
primes into the cylinder in the down stroke, it must remain on the top of the piston until it strikes 
against the cylinder cover in the up stroke, with more or less violence according to the quantity. From 
tJie incompressibihty of water, the effect is the same as if a piece of iron of equal thickness to the 


depth of water on the piston was suddenly inserted in its place. The tremendous effect sometimes pro- 
duced when a large engine breaks down from this cause, may easily be conceived ; for as the vacant 
space left for clearance at the top of the cylinder is generally about the same depth it large as in 
small engines, the intruding body of water strikes the cylinder cover with a proportionally greater force. 
Generally the accident does not end with merely straining or breaking the crank-pin, whijh maybe the 
extent of the injury in small engines ; but the momentum of the beam is added to that of the fly-wheel, 
and their combined force is exerted directly in splitting the cylinder, or tearing off the cylinder cover, 
thence effectually demolishing all the rods and gearing. Priming arises from insufficient steam room, an 
inadequate area of water-level, or the use of dirty water in the boiler ; the last of these instigations 
may be remedied by the use of collecting vessels, but the other defects are only to be corrected either 
by a suitable enlargement of the boiler, or by increasing the pressure and working more expansively. 
Closing the throttle- valves of an engine partially will generally diminish the amount of priming, and 
opening the safety-valve suddenly will generally set it astir. A steam vessel coming from salt into 
fresh water is much more liable to prime than if she had remained in salt water, or never ventured out 
of fresh. This is to be accounted for by the higher heat at which salt water boils, so that casting iVesh 
water among it is in some measure like casting water among molten metal, and the priming is in this 
case the effect of the rapid production of steam. One of the best palliatives of priming appears to be 
the interposition of a perforated plate between the steam space and the water. The water appeurs to 
be broken up in dashing against a plate of this description, and the steam is liberated from its embrace. 
In cases in which an addition is made to a boiler or steam-chest, it will be the best way not at cut out 
a large hole in the boiler-shell for establishing a communication with the new chamber, but to bore a 
number of small holes for this purpose, so as to form a kind of sieve, through which a ru^h of wat3r 
cannot ascend. In locomotives the same end is attained by the use of a perforated steam-pipe extend- 
ing from end to end of the boiler. Such a contrivance draws the steam off equally from the surface 
instead of taking it from any one part; and boilers provided with it are enabled to work with so small 
a steam-space that the steam-domes are now being taken away from locomotives altogether. This ex- 
pedient has not yet been adopted in steam vessels, though it appears to be applicable to them also with 
advantage. In some boilers priming appears to be mainly caused by a malformation which prevents 
the water from circulating freely, and the steam has therefore to pass up through the water, occasioning 
a great agitation, instead of the water being enabled to circulate with the ascending steam. The evil 
may be mitigated in such cases by the addition of pipes to the exterior of the boiler, which will permit 
a descending current to lie established, to replace the water carried upward by the steam. This ten- 
dency of the water to rise into the cylinder is always considerably promoted by the very usual situation 
of the steam induction-pipe at the back end of the boiler, and seems to arise partly from the constant 
circulation of the water, which causes a current at the surface to set in the direction of the length of the 
boiler from the front end to the back. This circulation of water takes place in all oblong boilers, with 
a certain velocity depending on the ratio that the intensity of the heat in the furnace bears to the quantity 
cf water to be kept heated, and is entirely independent of other causes, producing waves, which take their 
rise over the fire, and gradually increase in height as they pass towards the back part of the boiler. 

That waves are always generated within a long boiler, when the engine is about to prime, is a sin- 
gular but well-ascertained fact, as is shown by the frequent great and sudden depressions of the float at 
such times, especially if the latter happens to be placed at the contrary end of the boiler to that where 
the steam-pipe is fixed. In watching the rapidly-successive alternate elevations and depressions of the 
indicator, buoy, or float of a boiler in this condition, the priming may frequently he observed to recur 
periodically after intervals of a certain number of strokes, provided that the state of the fire and the 
load on the engine continue perfectly uniform. For the economical combustion of fuel, and arrangement 
of grates, see Fuel. 

Sinol-e Prevention. — Hitherto, the practice has been to exclude as much air and heap on as much 
coal as possible, thus preventing a sufficient quantity of the common atmosphere getting into the furnace 
to secure complete combustion. The consequence was the gases were too slowly evolved, and passed 
away into the chimney in dense black columns, to poison the air of the surrounding neighborhood. This 
is prevented now, however, by a moderate enlargement of the fire-beds and flues, and the introduction 
of air to the surface of the fire through perforated doors, and plates placed between them and the fire. 
The furnace itself being constructed to admit the quantity of air required, for perfect combustion, the 
perforated plates secure such a mechanical division and distribution of the common atmosphere as to in- 
sure its becoming instantaneously hsated, and promoting instead of retarding, as a column of cold air 
does, in a great degree the combustion sought. The whole mystery of all the smoke-preventing appa- 
ratuses now in public favor lies in this simple secret. The following is an analysis of experiments which 
have been made with Mr. Williams' Smoke Prevention apparatus. With the air wholly excluded, 251 
lbs. of coal were consumed per hour, 1,239 lbs. of water were evaporated, the Pyrometrical heat being 
381° ; whereas, with the air admitted, the consumption of coal was only 236 lbs. per hour, the water 
evaporated 1662 lbs., and the temperature, as indicated by the Pyrometer, 901° ; thus showing an im- 
mense saving of fuel and an extraordinary increase in the quantity of water evaporated, us indicated by 
the Tyrometric action. 

BOILER PLATES, Machine for punching.— Fig. 493 is an elevation, Fig. 494 a plan, and Fig. 495 a 
side view of a punchiug-machine on a very improved principle, whereby the plates required for boilera 
and other purposes may be punched with the greatest possible accuracy, insuring at the same time very 
superior workmanship and great dispatch. It is usual in all ordinary punching-machines, first of all to 
mark out all the rivet-holes in the plate, by a template, with white paint, and then to place it as near 
as the eye will permit under the punch ; by the contrivance of this machine, this operation is entirely 
dispensed with, it being only necessary to fix the plate to a travelling table, and then to adjust the va- 
rious parts of the machine to the proper distance required between the rivets. 


The large cast-iron frame p carries the several parts of the machinery; and also the two plummer 
blocks for°supporting the bearings of the lying shaft a, running the whole length of the building, for the 
purpose of working "other machines ; tins frame is securely bolted to the wall which, added to its own 
weight, gives it great stability. 

On the shafts a, connected together by the two coupling-boxes, is placed the crank 6, the motion 
being communicated through the crank-pin to a connecting-rod c, to which is attached the upper lever d, 
being always at work, while the shaft a is revolving ; the fulcrum of this lever is on the frame p. A 
lower lever e for raising and depressing the punchiug frame / has also its fulcrum on the same frame 
this last lever working only when the punching operation is being performed. On the top of th 
frame p is a lever and long rods e' for engaging and disengaging the machinery. The side view lcpre- 
sented by Fig. 495, shows the machine at work, and by drawing down the lever e', connected by the 
rods to the counterbalance weight, which will allow it to remain steady in any position, they are 
disenn-ao'ed from the pin on the lever d, which at once ceases to communicate the motion to the lower 
or punching lever e; thus it will easily be understood that those parts of the machine constantly at 
work, are the lying shaft a, the crank b, the connecting-rod c, and the upper lever d. 

The slide / "for carrying the punches, works between V's, Fig. -49-1 ; one is fixed to the frame p by 
adjusting-screws, both on its face and sides, and by the curious shape given to the end of the lever c, 
this slide is made to rise and fall, the counterbalance weight and lever g being connected by two short 
links ; on the bottom of the slide is screwed a small frame for carrying the punches, which may be 
taken out and replaced by others. The dies i, in which the punches work, are placed in a frame bolted 
to the frame p, and by unscrewing the small adjusting-screws, these may be taken out and replaced by 
others suitable to the different-sized punches that may be required. On the under side of the frame p 
is screwed a small stop, by which the circle punched from the plate is forced out as the slide rises. 

In the front of the machine is placed a long table, supported by the carriages o, consisting of two 
columns and diagonal frame, having bolted to them two long bars, upon which the moveable table is 
made to slide ; this table, as will be seen by Fig. 494, has a number of holes by which the plate to be 
punched is secured by clamps ; it is advanced by the rope or chain n passing under the pulley, Figs. 
493 and 494, and over a second one hung from the ceding of the building, to which is connected a 
weight sufficiently heavy to draw forward the table and plate fixed to it ; after travelling the length of 
the table o, it may be brought back by turning the winch-handle and spindle I, on which is a pinion for 
working the rack, fixed to the under side of the moveable table m. 

By a very ingenious contrivance, forming part of this machine, the rivet-holes of boilers may be 
punched to very different pitches, a thing very much wanted in such cases as the repairing of old boders, 
or replacing an old plate by a new one, where it is of the utmost importance to have the rivet-holes 
coinciding with the greatest accuracy, which may be better understood by supposing that in the length 
of a plate, one, two, or three additional rivet-hcles may be required, which distance would have to be 
equally divided in the whole length of the plat".. A description of this part of the machine will fully 
show how this operation is performed. On the end of the punching-lever e is screwed a small plate 
with a pin f, adjustable by a screw working in the short mortise, Fig. 495 ; on the frame p is bolted a 
fulcrum piece for the lever and counterbalance weight j ; to this lever a long rod is connected at its 
lower end, passing under the table m, and the lever r is fixed to it, as will be seen by the dotted lines 
in Fig. 494; it has also two stops or projecting pieces r'r' on its surface. A second lever s has its 
fi Jcrum fixed to the table o, one end of this lever being connected to the lever r, while the opposite end 
has on its surface two small puis s' s' ; the fulcrum s" of this lever is adjustable by the two small 
screws shown in the plan, Fig. 494. A long notched bar k is fixed to the under side of the table m by 
screws, and the bar t has its fulcrum t' also fixed to it ; this latter bar t is moveable on its centre, and 
may be placed at any angle by an adjusting-screw working in a mortise t", where it may be fixed in 
any required position, as will be seen ; it is by the angle given to this bar, that the regular increase of 
distance is obtained between the rivets. This is effected in the following manner : — As the lever c 
works on its centre, the pin j' to wluch it is fixed, strikes as it descends on the end of the lever j ; its 
motion is then communicated to the long rod, passing under the table, for working the lever r back- 
wards and forwards, it being fixed to the rod ; as the latter lever moves, it alternately engages and 
disengages the stop or projecting pieces )•' )•' from the notched bar, allowing it at the same time to slide ' 
forward the distance between the rivets ; while the bar t placed at the required angle, and working 
between the pins s' s' on the lever «, immediately effects the distance travelled by the lever r, which it 
shortens ; by this arrangement the machine is made quite self-acting, but it may also be worked by the 
handle on the end of the rod j. 

When it is required to change the punches h for different-sized holes, it is necessary, when replaced, 
to adjust them to the greatest possible accuracy in the dies i ; this could not (be done without stopping 
the whole line of shaft a, were it not for a provision made for that purpose ; in such i case, the key in 
the upper part of the connecting-rod c is withdrawn, a block of wood is then placed between the frame 
and the lever d, whose fulcrum is on the side of the frame jr., upon which it rests. It is of coiu-se under- 
stood that the puncliing-lever d is at rest, being disengaged from the pin e'; the result of this is the 
working of the long mortise of the connecting-rod up and down on the pin, without communicating any 
motion whatever; and by the lever q, worked gently by hand, and shown dotted in Figs. 494 and 495, 
the punching-lever e can be raised and lowered, communicating its alternate motion to the slide-frame, 
by which means the punches are with great facility adjusted in the dies i. 

The jaws in the frame p are much strengthened by placing a square wrought-iron bar between them, 
in places provided for the purpose. 

From the above description, it will be seen that the advantages possessed by this machine, more than 
compensate for the increased number of its parts, which are but few when compared with its superiority 
over those of ordinary construction. 



a Shaft running through building. 

b Crunk. 

c Connecting-rod. 

d Upper lever worked by connecting- 
rod c. 

c Lower or punching lever engaged 
or disengaged by means of rods, 
levers, and pin c. 

f Punching-frame raised or depressed 
by lever c, and counterbalance 
weight g. 

g Lever and" counterbalance weight. 

A Punches. 

i Die-frame. 

> Self-acting rods, levers, and counter- 
balance weight, for engaging and 
disengaging notched bar "from 
stops r r\ worked by pin /. 

k Notched bar fixed to table and 
stopped by projecting stops k 
alternately on either side fur each 
Handle, pinion, and rack, for ad- 
vancing table by hand. 

m Moveable table for carrying plate 
to be punched, drawn along by 
rope or chain running over pul- 
ley n. 

Fixed tables supported by columns. 

p Frame for carrying machinery. 

q Lever for raising puuchiiuj-Iever 
when the punch is required to 
bechanced without stopping the 
length of shaft. 



a Shaft running through building. 

b Crank. 

e Coimecting-rod. 

d Upper lever worked by connecting-rod e. 

c Lower or punching lever engaged or disen- 
gaged by means of rods, levers, and pin c. 

f Punching-frame raised or depressed by lever 
c, and counterbalance weighty. 

g Lever and counterbalance weight. 

A Punches 

i Die-frame. 

to;QiXr::fct::®:::0:i.Q ::o L"C ircia. 
i } o o m b o I o 1 ■ o I Q i J m o o 

j SflJ : ai.'ti]]g rods, levers, and counterbalance 
weight, for engaging and diseii^imirig 
notched bar from stops r r', worked by 

k Notched bar fixed to table and stopped by 
projecting stops k alternately on either 
side for each rivet. 

/ Handle, pinion, and rack, for advancing 
table by hand. 

m Moveable table for carrying plate to be 
a punched, drawn along by rope or chaia 
v running over pulley n. 


Rope and pulley for drawing along 

table 77i. 

* Fixed table supported by columns. 

p Frame for carrying machinery! 

q Lever for laising punching-lever 

when the punch is required to be 

changed without stopping the 
length of shaft. 

r Lever fixed at one end to rod j; on 
this lever is fixed two smali pro- 
jecting pieces r r\ 

s Lever with two guide-pins s\ having 

a moveable centre at j". 
t Car for regulating the pitch of lire*- 
holes, working between pins »' *'; 
it has a fixed centre at t\ and 
may be placed at any angle by 
sliding in groove i". 


BOLTING-MILL, for four. — A bolting-mill is the general name of a place -where meal is sifted. 
But here the subject in question is particularly a dressing or bolting machine in common mills, by which 
either the bran is separated from the flour or meai, or the ground grain, ore, &c, is refined. The bolt- 
ino- machines most in use are — 1st. The common loiter ; 2d. The rotative cylindric or prismatic holier ; and 
3d. the brush-bolter. Though they differ from each other in structure, the substantial arrangement 
consists in a kind of sieve of wire or horsehair, or of cotton or silk texture, of bolting cloth or of silk- 
gauze, either of which stuff is used according to the fineness of the nietd required ; the meshes or per- 
forations of the one being smaller than those of another. 

The peculiarity of the common bolter is, that the sifting is produced by its shaking motion ; that of the 
cylindrical or prismatic bolter is, that the sifting is effected by its rotative motion, either alone, or by 
co-operation of the centrifugal power, or of beaters or similar apparatus. 

The peculiarity of the brush-bolter is, that the sifting is effected by brush's placed in the interior of 
the bolter itself, which latter discharges its coarser contents into the bran-chest ; while the meal or flour 
is taken up to the bolting-hutch. 

The arrangement of the improved bolter in general use, will be perceived by Figs. 463, 464, 465, and 
466, where Fig. 463 represents the bolting-machine in longitudinal section; Fig. 464 ground-plan, (but 
without the lid of the bolting-hutch :) Fig. 465 front, and Fig. 466 side-view of the hind part, together 
with the mechanism for effecting the shaking motion. 

The oblong and closed bolting-hutch, marked by a a, is fastened to the meal-bench b ; and in its in- 
terior, at an angle of 15, or, at the most, 30 degrees, is placed the bolter or sifter cc, whose upper end 
is fastened to the scuttle d, Figs. 463 and 464, and whose lower end discharges its contents at the 
fore side of the hutch a a. 

The bolter consists commonly of bolting-cloth or silk-gauze, of which two strips from 6 to 7 feet in 
length, and from 14 to 16 inches in breadth each, are sewed together lengthwise. The seams are 
edged, two inches broad ; and the two ends of the bolter are likewise bordered with leather, for the 
purpose of fixing iron rings. The ring at the upper end is quadrangular, yet with rounded corners ; it 
is S inches broad, and from 5 to 6 inches diameter. At about 2 feet down from the upper end of 
the bolter, two handles, (called bolter-ears, and marked by the letter e,) of strong sole-leather, are sewed 
to the sides, to serve for the reception of two arms//! of the apparatus for effecting the sh akin g mo- 
tion. The lower end of the tight-stretched bolter is placed in the aperture cut out in the slide g on the 
outside of the bolting-hutch ; the shaking-arms ff, which are either covered with tin-plate, or with ends 
of cast-iron, are to be put through the two bolter-ears e ■ and the upper end of the sifter is to be placed 
on the outside of the scuttle d, in the notch of the wooden ledge h, Fig. 463, and fixed by the iron cramp ;. 
At the lower end the screws Jc k of the slide g are designed to stretch the bolter as required. 

The motion of the bolter may either be horizontal or perpendicular. The former is most general, 
as the bolter is more worn by the perpendicular motion. But it may be asserted that the case is 
almost entirely the reverse. For by the lateral motion the sides of the bolter are very much tossed, 
and so their threads too much stretched, especially when the shaking-arms // stand out straight from the 
shaking-axis, forming thus an acute angle with the bolter. By the perpendicular motion'the bolter is 
also violently tossed ; however, this inconvenience may be removed by using curved arms, (like that 
marked by /'in Fig. 463.) instead of rectilinear ones, and made either of timber or iron. 

The vertical shaking motion of the bolter is produced in the following simple way : At the axis' I, 
placed horizontally beneath the sifter, are fixed the two shakii.g-arms//; also at its projection the bent 
arm m, called the bolter, in winch the bolter-tongue is, by means of a peg, fastened in a manner which 
allows of its turning. The bolter-tongue is pressed against the horizontal arm o of a vertical axis p, oy 
the wooden or steel spring g, so firinly and continually that a retrograde motion results from the re- 
bounding of this spring, while the advancing motion is effected by a second arm r of the axis p, whicli 
beats against three tenons t, and is pushed off again by them. 

The power of this shaking motion can be modified according to the required fineness of the flour, or 
to the more or less fine bolting-cloth; and this is effected by displacing the bolter-tongue n in the 
wheel-scissors m, for which purpose both are perforated. However, the bolter is not suffered to move 
more than 3 inches up and down, as this is sufficient even for the coarsest grit, while a more vigorous 
movement would wear the bolter too much. 

The upper millstone in a common mill, of 3 feet in diameter, making from 140 to 180 rotations a 
minute, each bolter, brought in connection with a set of such stones, will be moved up and down thrice 
bo often, or 420 to 540 times in a minute. In order to be enabled to look frequently at the bolter, there 
is made in one of the side partitions of the bolting-hutch a large square aperture uu, commonly covered 
with a linen cloth v, Fig, 464. Another aperture w, about 6 inches high and wide, at the bottom of the 
hutch, is provided with a slide of wood or tin-plate, and serves as an outlet for the flour. 

Beneath the lower end, or mouth of the bolter, is a small gutter x, made of wood or tin-plate, in orde> 
to fatilitate the emptying of the grit or bran into the bran-chest below. The mouth of the bolter is 
:overed with a cloth y, Fig. 465, pressed towards the mouth of the bow z, to prevent the flour-dust, 
joined to the grit and bran, from dusting away. The aperture in the side-partition, fig. 463, « «, is 
leside the curtain, fig. 464, v, closed with a door or slide, while on the other hand, the bran-chest is 1 J 
feet in length, and closed tightlv. 

The bolting-cloth used in bolting-mills consists generally of woollen, more seldom of silk texture, and 
is glued or gummed in a particular manner. According to the species of corn to be bolted, and to tho 
fineness of the flour, the cloth is coarse or fine, both in the threads and the size of its perforations or 
meshes.^ There are more than a dozen sorts of cloth, which are selected according to the quantity of 
meshes hi an inch square. The cloth is commonly from 14 to 16 inches broad, thus being adapted for 
the use of bolters from 10 to 12 inches in diameter. The English manufacture bolting-cloth noted ftu 
ts good quality and durability ; there are also in Germany superior manufacturers of this article 
sspecially at Linz, Berlin, and Breslau. The best quality bolting-cloth and silk-gauze is' fabricated bi 


Dufour & Co., at Thai, in the Swiss canton of St. Gall, by Hennecart, at St. Quentin, in France, and by 
Harlan Star, in Holland. 

We shall now describe tbose bolting-mills where the cylindrical bolter is used. 

Formerly, in England and the United States, a bolting-mill of this description was used, in which the 
cylindrical bolter, put in circular motion with great celerity, consists of a kind of reel, framed in t he 
following manner : — From a somewhat inclined axis, like radii, six arms or spokes project, which are K:n- 
nected with each other by six laths running parallel with the axis. This cylindrical frame is commonly, 
at the upper end, 22i inches diameter, but at the lower end only 20£ inches, (in this case it is called 
taper-reel ;) sometimes it is at both ends 22 J inches diameter, in which case it is called an eqiial-rccl. 
The wider cylindrical bolter encloses the frame, and is at both ends (which are lined with leather) 
fastened to it. In the bolting-hutch are placed six wooden beaters, whose points stand off half an inch 
from those of the spokes. Now, as soon as the bolting-cloth is swelled by the rotation and centrifugal 
power, it strikes violently upon these beaters, and thus the finer elements of the flour are forced 
through the sides of the bolter, while the grit and bran proceed along the whole bolter into the bran- 
chest at the outside of *he bolting-hutch. 

Yet this bolting apparatus was not much adapted to the purpose, because the ends of the bolter 
could not be fixed firmly enough to prevent its unsteady, swinging motion, and its too violent striking 
upon the beaters, by which the bolting cloth soon became defective. However, at present this bolting- 
mill is substantially improved by James Ayton. 

Fig. 467 gives a side view of this improved machine, without the bolter, and without the front of 
the hutch. In the frame of the bolting-hutch a a, the apparatus is placed obliquely. By the axis b b, 
(made of forged iron,) and the disk c, the bolting-machine is brought in rotation. At the axis b b are 
fixed the two naves d and e, in a proper manner, and into both are placed four spokes //, at right angles 
with each other. From each spoke to the corresponding opposite one, or from /to/, is distended a 
strip of bolting-cloth or duck g, 5 to 6 inches broad, fixed at the extremities of the spokes. The strip- 
in the interior of the bol f er form a kind of fanning-machine of about 20 inches diameter. Above 
file nave d is another one h, from which project six iron spokes, bent upwards, and connected with each 
other at their points by the wooden ring k, whose diameter is equal to that of the fanning-machine. 
Below the board partition / 1, that separates the flour-hutch m from the bran-chest n, is a third nave o, 
from which project six steel springs p, whose points are bent into hooks, carefully rounded off and pol- 
ished, that the handles of the bolter (which are fixed to them) may be spared as much as possible. 
This nave, which by Fig. 46S is twice represented on a larger scale, consists of three hoops o } r, of 
which the inner q is fastened to the square axis b b ; the middle o revolves round the hoop q, and the 
outer r is fastened to the hoop q by four screws. 

The bolter surrounding the fan-shaped reel is, by means of its handles at the lower end. fixed at the 
hooks of the six steel springs p ; wliile its upper end, above the wooden ring k, is simply drawn to- 
gether by a cord or string. As soon as the reel is in rapid rotation, the pressure of the air, produced 
by the fans and the centrifugal power, will swell the bolter, which at the same time is kept at a uni- 
form concentric tension by the elasticity of the steel springs p. 

Another substantial improvement of Ayton's bolting-mill is, that the six beaters s, lying round the 
bolter may, according to circumstances, be placed more or less near to it, even during the rotation. 
The manner of this arrangement may be perceived by Fig. 469, where the macliinery, Fig. 467, is repre- 
sented in a view from beliind or before. On the outside of each of the partitions 11 and tt, Fig. 467, is 
a br -ad iron ring u, Fig. 469, revolving round the axis 6, in the small furrows of the six cramps marked 
with v. In both of these rings (on the front and back) are cut six eccentric slits w to, behind which, in 
the board partitions, there are cut out as many other slits, like radii of the axis b b, so that both kinds 
of slits are crossing each other. The beaters s s. Fig. 467, are (by means of screws x) brought into con- 
nection with the slits in such a manner, that they are moved to aud fro in the slits of the partitions / 1 
and 1 1, and thus approach and turn off from the bolter, as soon as the outside rings u (whicl» are not 
connected with the axis b b itself) are turned round by the dented wheels y, Fig. 469. The whole 
perimeter of the rings is dented ; only a part of it is shown in Fig. 469. The dented wheels are con- 
nected with another axis different from that marked with b b. 

Through the hopper z, Fig. 467, is constantly running the ground grain as required for bolting ; so 
that from the other end of the bolting-hutch only grit or bran, without mixture of flour, runs out. 

This improved bolting- mill has this substantial advantage over the older one — that the movement of 
the air within the bolter is produced by the fans instead of the reel, and drives the flour towards the 
periphery in a more complete manner. Thus the flour gets easily through the perforations of the 
bolting-cloth, whose obstruction is almost entirely prevented by the trembling motion of the steel 
springs p. The beaters are also arranged so that they cannot much wear out the bolter. 

While by the older machinery (with 170 to 200 rotations a minute) only two and a half to three sacks 
(measuring three bushels each) of grit are said to have been bolted in an hour, Ayton's unproved mill 
bolts four sacks in the same time. 

Notwithstanding this favorable result, the improved bolting-mill is not much used, for the reason that 
the bolter (as the weakest and most expensive part) is yet damaged by the beaters. The cylindrical 
bolter has recently been supplanted by a hexagonal or octagonal one, with great success. 

Figs. 470 and 471 show the frame of this bolting-machine (which is in very general use in this coun- 
try) in longitudinal section and front view. The front partition is omitted, to get a better view of the 

These bolters are made exclusively of silk bolting-cloth, manufactured by Harlem Star, in Holland. 
For two sets of five-feet millstones there are generally made boltei-s of 28 inches in diameter and of 90 
feet in length, and of three different sorts of cloth ; that is, 60 feet of the finest sort, No. 10 or 11 ; 24 
feet of the middling sort, No. 5 or 9 ; and the remaining 6 feet (60+24-1-6=90) of /he thud or coarsest 
port, No. 2, which latter is intended for separating the finer bran from the coarser. 


The cloih is tcntered round wooden frames similar to the above-described reek, of hexagonal or oc 
ta^onal form, 20 inches in diameter, and from IS to 20 feet in length. The cloth is fastened with pin? 
to'the wooden rings at both ends of the frame, and to six or eight laths running parallel with the axis, 
and resting on spokes. 

Such bolters as a o, Fi's. 470 and 471, are commonly placed four in one hutch b b, that is, two above 
and two below, as in Figs. 470 and 471. They are placed somewhat obliquely, and, by means of the mo- 
tive power c c, revolved all together by the wheel d of the axis, which also turns the wheel e. Each 
bolter makes generally 25 rotations in a minute. The flour-conveyers, / and g, are commonly put in 
motion by straps, (like the strap h, in Fig. 470,) they being highly adapted to the purpose, and more- 
over simple and cheap. The conveyers are intended to remove immediately the bolted flour from the 
hutch of each pair of bolters without opening the hutch. 

The "round grain passes through the common plate-iron gutters i i into the two superior bolters, 
(where the cloth is of finer quality,) in such quantity as may be easily bolted by them. The mechan- 
ism applied for this purpose will be described below. The flour bolted in the upper half of these two 
bolters is somewhat finer than that bolted in their lower half, the former therelbre being called extra- 
superfine, and the latter superfine. All this flour falls through the oblique partitions ft ft, Fig. 471, into 
the trough / of the upper conveyer. The wheels m n, Fig. 470, moving this conveyer, are covered by 
the roof o. The coarser parts, or the grit and bran, issuing from the mouth of the bolter, fall into the 
partition p of the bolting-hutch, and then, by means of the oblique board partition q, into the two lower 
bolters of coarser cloth a,. Thence the bolted flour goes into the trough r of the lower conveyers g, and 
the bran goes from the bolter's mouth through the gutter s, Fig. 470. 

The above-mentioned extra-superfine flour is, by means of the conveyer/, pushed to the wooden chan- 
nel (, through which it then goes off into the flour-box, while the superfine flour is, by the channel u, 
conveyed into the upper partition of the hutch, enclosing the two lower bolters Oj a,. Hence, mixed 
with the flour of these bolters, it is by the lower conveyer g pushed to the channel j>, through which it 
goes off into the meal-elevator, that brings it back to the hopper-boy. Thence, having been mingled with 
grit, it is conveyed once more into the bolter. In the case when the middling flour (or seconds) is ground 
for the second time, the flour bolted by the upper and lower bolters is intermixed and not reconveyed 
into the hopper-boy ; but the gutter or channel v is shut, and the strap h (moving the conveyer g) crossed, 
which lias the effect of conveying the flour to the gutter or channel w, (which then is to be shut up,) 
iVom whence it goes, together with the flour coming from the upper bolters down the gutter a*, into the 

The mechanism by which the ground grain or meal is conveyed into each of the two superior bolt- 
ers, is to be seen in Fig. 472, longitudinal section, and Fig. 473, front view, on a larger scale. The letter 
i/ marks a funnel, into which the ground mass falls clown from a hopper-boy in a higher story, and thence 
upon the moveable spout a, resting on the axis z. The channel i, Fig. 471, is connected with this spout. 
At the fore part of the spout's side-boards are the cross-rails /5, by which, and by wedges, the sha- 
king-bolt y is fastened. At the upper mouth of the bolters is a cast-iron cross I, Figs. 470 and 471, 
fastened to the axis, whose points are provided with heads, the forms of which may be seen by Figs. 
471 and 472. During the rotation of the bolters, these heads touch upon the end point of the shaking- 
bolt y, Fig. 472, which lifts the spout o up and down. Thus the spout is constantly in a shaking mo- 
tion, and the mass heaped in the funnel y is conveyed by the gutter i into the bolter a. By means of 
the shutter c the aperture at the bottom of the front partition of the funnel y can be widened or nar- 
rowed, according to circumstances. 

The conveyers f and g consist of a screw, as may be perceived by Fig. 474, where they are repre- 
sented on a larger scale. The chief part is commonly an octagonal strong wooden axis 1, round which, 
in a helix, are put small wooden square tables 2, 2, at right angles to the axis. 

These tables are generally 2| inches high and broad, and at the foot end half an inch thick, while 
the back lessens to a sharp edge. The front sides (which retain their right angle with the axis) take 
hold of the flour contained in the trough 3, and push it gradually on to the respective gutters. Beside 
the slides, shutting the gutters v, x, t, v, w, there are in the bottom of the conveyer-trough as many 
slides as possible, in order to prevent its obstruction during the movement of the conveyer. 

In the above-described bolters the pushing of the flour through the perforations of the bolting-cloth 
is produced in such a manner that the contents of the bolter are during its rotation cast up, and then by 
their own weight fall upon the under side of the bolter ; whereas, in the following rotative bolters (which 
in all other respects are arranged like the other just mentioned) the bolting is effected by beaters or 
other similar instruments. By this arrangement, the obstruction of the perforations is prevented with 
more success. 

Figs. 482 and 483 represent a bolter of this kind and its hutch in longitudinal and transverse sec- 
tions ; and Figs. 484 and 485 represent the bolter in transverse section, and in a side view. The hex- 
agonal wooden axis is marked by a a. From each of its six flat sides project six cylindrical staves b, 
of hard timber, and one inch in diameter, and placed at the distance of two or three feet from each 
other. The staves of every row are at their points connected with each other by a lath c, over which 
the bolting-cloth is tentered, and to which it is fastened with pins. Upon each staff is put a little tube 
of cast-iron, 1J to 2 pounds weight, 3 to 4 inches long, 2 inches in the outer diameter, and called beaters. 
During the rotation of the bolter, produced by the wheels e and /, Fig. 482, these beaters run up and 
down the staves, Fig. 4S4, and by their beating against the hard-wood supports g, Fig. 4S4, underneath 
the laths c, they prevent the obstruction of the perforations of the bolter. That the laths may not ba 
knocked off by this beating, there are commonly laid round bands either of leather or thin hoop-iron, 
Bee k k, Fig. 4S5. 

"Wliile the lower end of the bolter is left open to let out the grit or bran, the upper end is provided 
with a wooden crown i, Figs. 4S2 and 4S3, whose interior diameter leaves only as much room as is re 
quired for the plate-iron gutter ft, Fig. 482, by which the ground mass goes into the bolter. The crowo 




t is provided with a funnel I of tin-plate, for the purpose of retaining the grit or flour within the 

A bolter of this kind is commonly from 16 to 26 feet long, and 21 to 80 inches diameter, and inclines 
in the ratio of one-fifteenth to one-eighth of its length. Its silk bolting-cloth is selected out of two to five, 
and even still more numbers. The first sort covers the greatest part of the bolter from above, and then 
follow in succession the coarser qualities. According to the variety of the flour to be obtained, there 
are brought into connection with a set of 4 or 5 feet millstones, either one, or two, or more bolters, 
which are placed in the above manner, (see Figs. 470 and 471.) The most proper arrangement is, that 
the upper parts of the bolter (covered with the finer sorts of bolting-cloth) furnish the floui at once 
completely bolted, while the less fine grit of the other parts is to be ground and again bolted. 

The different qualities of flour or grit are taken up in separate partitions of the bolting-hutch, of wliicn 
a simple arrangement is represented by Figs. 482 and 483. The partitions n separate the lower part 
of the bolting-hutch mm into the partitions 1, 2, S, and 4, of which the first three take up three differ- 
ent sorts of Hour, while the partition 4 takes up the grit or bran issuing from the mouth of the bolter, 
and has on its outside a hole (with the slide o) through which the grit or bran comes out. The oblique 
tables pp, Fig. 4 S3, leave below an opening from 6 to 12 inches wide, through which the bolted flour 
falls into the partitions. Each of the latter, 1, 2, and 3, is provided with a valve, consisting of a frame 
covered with cloth, (see q, Fig. 482,) and whose hinges are marked by r r. The valve may be kept open 
by fastening it to the buttons s s, Fig. 483. 

Another proper arrangement for taking up the flour or grit, is shown by Figs. 486 and 487. Here the 
bottom b of the bolting-hutch a a, (which contains the same partitions as the other ones just described,) 
runs out in a slope sidewise, through which the flour falling from the bolter accumulates at the side- 
wall cc, Fig. 487, and thus runs easily through the opening d, into the bag/, as soon as the slide e is 
shut up. As many as convenient are placed before a flour-partition, Fig. 486. They are put up and 
taken away in the following simple manner : At the sack-mouth i, beneath the opening d, on which 
rests the sloping bottom b, are put in two screws h h. Their ends are crooked into hooks which grasp 
the leather rim i of the sack. (See It beneath the opening d. Fig. 487.) About 3 or 5 feet above each 
sack projects a rafter k, from which hangs down a thong I, with forceps m and n, to take hold of the rim 
of the sack. 

It may be finally remarked, that it has been tried to supplant the beaters above described, (see Fig. 
484,) by another contrivance represented by Figs. 488 and 489 in side and front views. The chief part 
consists of a thick steel button marked 6, Fig. 4S8, fixed at the upper pivot of the bolter's axis 6, Fig. 
488. The steel button turns round on a strong and well-polished steel plate c, inserted into the pivot- 
base d. Now the axis in turning round is by the three protuberances lifted up and down, and thus 
constantly kept in a shaking motion. In this way the obstruction of the perforations of the bolting- 
cloth is prevented as well as by the beaters. 

The brush-bolter, or cylindrical dressing-machine, as it is styled, is in many mills used conjointly with 
Ayton's improved bolting-machine, into which latter the grit and bran is brought after they have been 
bolted in the dressing-machine. 

Fig. 475 gives a side view of the common brush-bolter, while Figs. 476 and 477 represent an un- 
proved machine of tins kind in transverse and longitudinal section, several parts of which are illustrated 
by Figs. 478 and 479, (on a large scale,) and 480 and 481. 

The bolter, both of the common and improved macliine, is cylindrical, covered by a bolting-cloth made 
of wire-texture, and placed obliquely in the bolting-hutch. (See Figs. 475, 476, and 477.) The bolting- 
cloth in Fig. 475 is directly fixed to the bolting-frame ; but in Figs. 476 and 477 it is kept suspended 
by long screw-bolts q q, fixed at the roof of the bolting-hutch. (See Figs. 476, 477, 480, and 481.) The 
cylindrical sieve-frame of the common macliine, Fig. 475, consists of staves bb, fixed round the disks 
c c and at the felloes d. The interior periphery of this frame is covered with wire-gauze of different 
fineness — the first number fixed at the upper end, and the less fine sorts following in succession, just in 
the same way as has been mentioned. 

The sieve-frame of the improved machine consists of two semi-cylinders, (see Figs. 477, 4S0, and 
481,) whose side-boards ee are laid and screwed together, thus forming a full cylinder. 

Within this cylindrical sieve is, exactly in its axis, placed the shaft//; (made of wrought-iron hi the 
machines represented in Figs. 475 and 476,) which is provided with three 'disk-wheels ggg, Fig. 477. On 
the periphery of these wheels are put in eight brushes of hog's bristles h, (see Figs. 478 and 479,) in 
the maimer illustrated, not only by Fig. 477, but also by Fig. 478, where the wheel-periphery is marked 
by ffff, ar >d the brushes by hh; while the outer circle signifies the inner periphery of the cylindrical 
sieve. The shaft//, Fig. 477, is turned by the disk i, and during its rotation the brushes touch the inner 
periphery of the cylindrical sieve as much as required, to prevent the obstruction of the perforations 
by flour. In case the brushes should be worn, they can be screwed more forward by boxes it k, Fig. 478. 

At the upper and lower end of the cylindrical sieve are the wooden rings I and m, Fig. 477. fastened 
by means of screws. They are in the periphery somewhat notched, as may be seen by m, Kg. 481 
Tc the upper ring I, Fig. 477 is tied, by means of a cord, the leather strip n, which is glued or nailed on 
the bolting-hutch a a. By this arrangement the ground mass, coming out by the spout o, is taken up 
here, and conveyed to the cylinder. The ring m, at the lower end, serves as a link between the parti- 
tion-boards p p. 

In order to establish equality in the brushing of the sieve, this latter, or the cylindrical bolter, is, by 
means of four screw-bolts q q, kept in suspension, and may, according to circumstances, be wound up 
and lowered, for which purpose the nuts are winged. The screw-bolts are at their ends provided with 
hooks r r, Figs. 4S0 and 481, which take hold of two side-laths b b, Fig. 481, of the cylindrical frame 01 
the sieve On the other hand the brush-cylinder, whose shaft //rests on the sliding-rail s, can also b« 
displaced, either up or down, by the nut of the screw t. 

The hopper, which holds the ground grain, is marked by u, Fig. 477, and the moveable spout con- 





Ducted with it by o. This spout is shaken by a nave v, fixed at the shaft//, -which beats during the 
rotation against a tack at the bottom of the shoe. By the slide at v>, the quantity of ground grain in 
the shoe can be increased or decreased. The slide .r, which in Fig. 477 is closed, is shut up in Fig. 47G. 

A cylindrical sieve or bolter of this kind is commonly covered with four or five different numbers of 
wire-texture, through which the different qualities are bolted, and taken up by the corresponding par- 
titions 1, 2, 3, 4, and 5, whence the flour is easily taken out through the side-openings, until then closed 
by slides. The bran falls into the partition 6. 

The fineness of the texture is commonly in the ratio of 64, 00, 56, 88, and 16 meshes to the square 
inch. Experience lias taught, that the best arrangement is to cover the frame from above, first with 
gauze or texture of GO meshes, and to follow in succession that of 64, 56, 38, and 16 meshes. The 
gauze of 60 meshes furnishes as fine flour as that of 64, which is owing to the circumstance that the 
flcur in the uppermost part of the bolter is not so much exposed to the influence of the brushes, and 
that the finest quality of flour is more sticky or viscous than the coarser qualities. 

By the rotation in one and the same direction, the bristles of the brushes must at last be bent to one 
side, and thus lose their efficacy. To remedy this, an arrangement is made by which the brush-reel 
turns alternately to the right and left. This is easily effected by double wheels or thong-disks. 

A small brush-cylinder has been invented by James Murphy, of Zanesville, 0., which is to be placed 
at the outside of the above-describeu cylindrical sieve, that is, everywhere on its periphery brushed by 
it. By this operation the obstruction of the meshes is completely prevented. Mr. Murphy uses thin 
hoops and ribs of cast-iron fof constructing the sieve-frames, instead of the above-described wooden 
felloes and laths. 

BOLTS, (iron.) The pieces of iron used for securing framing together, and much employed in timber 
work ; they are formed of wrought-iron, either square or cylindrical, with a square head at one end, 
and a screw and nut at the other ; a plate of iron, termed a washer, being interposed between the 
surface of the wood and the head and nut, to protect the former from damage during the process of 
screwing up. 

BOLSTERS. The pieces of timber used in the construction of the centres of arches, and running 
across from one rib to another, for the purpose of supporting the voussoirs. A piece of timber, em- 
ployed in a somewhat similar manner to a corbel, is also termed a bender ; which are much employed 
in timber bridges. 

BOND. The union or tie of the several stones or bricks forming a wall. The great principle in all bond 
is to provide against settlements : the vertical joints of a course should, therefore, be exactly midway 
between those below — in other words, break joint with them; and in no case should the joints of one 
course be carried up over those of the one below it. 

The bricks or stones lying lengthwise, in the longitudinal direction of the wall, are called stretchers • 
and those placed lengthwise across the wall, headers. 

490 491. 

lpk\\\ o 


A,\<l « 1 1 1 I 1 I I 1 

%v\'l 1. 1 1 1 

\.\\: ll i il i 1 1 1: i 

4 1 1 li II 1 

Old English Bond, or Block-bond. 

Flemish Bond. 

Bond may be described generally to be of three kinds. In English bond the courses are alternately 
all headers and all stretchers, and when the backs of each course are laid alternately header and stretcher 
it is called Flemish Bond ; this description of tie is also known by the name of header and stretcher 
particularly in stone-work. 

Cross-bond. Combined Cross and Block bond. 

The cross-bond — mostly used in Germany by bricklayers — differs from the old English or block 
bond, by the change of the second stretcher-line, so that the joints of the second come in the middle of 
the first, and the same position of stretchers comes back only every fifth line. This bond gives besides 
a very neat appearance, and is therefore used wherever a nice building is to be erected. The strongest 
tie is given to a wall by combining the block and cross-bond, so that the extrados is put up iu cross- 
bond, the intrados in block-bond, as shown in the figure. The reason of it is, if a settling of the 
wall happens, so that the joints open, all other bonds give only in the vertical, a crooked breaking 
line ; but this combined-bond requires a crooked breaking-line in the horizontal direction beside? ; it Li 
therefi re applied where a neat appearance and great strength are required. 


BONES. See Animal Kingdom, materials from used in the mechanical and ornamental arts. 

BORING MACHINE, Vertical : by Messrs. Nasmyth, Gaskell & Co. The many advantages derived 
by this arrangement of a vertical boring maeliine over those where the work is placed in a horizontal 
position, may perhaps be unknown to persons unacquainted with the general character of machinery ; 
it may not be unadvisable to point out a few of the principal features showing the superiority of this 

In the first place, the arrangements of its parts ; the manner in which the cylinder is placed, namely, 
its vertical position, thereby doing away entirely with all the injurious effects produced by the weight 
of the body being planed or bored ; thus obviating all tendency to distort its figure, which is the case 
where the operation is performed by the horizontal system, and where the sides are bulged out from 
the weight of the upper part ; this may be better understood by forming a cylinder of thin paper, which 
will be found to widen in the middle and assume an oval form from its own weight. 

This alteration of form is found to be quite sensible when the cylinders are of large diameters. 
Another great advantage of this system of vertical boring, is avoiding all risk of flexure in the boring- 
bar, upou which the cutter wheel or head is fixed for carrying the boring-tools ; this bar has a tendency 
to bend down in the centre to a curve, instead of keeping a perfectly straight line, transferring the 
figure assumed by the bar to the surface of the cylinder ; but this will much depend both on its length 
and diameter. 

Another advantage of this maeliine is, that the cutters are kept clear of the borings, which fall to 
the bottom of the cylinder as fast as they are cut. By this superior arrangement all these objections 
are entirely removed, thus avoiding all the tendency gravity has in altering the trueness of the cylinder 
or the bar ; added to these, the power requisite to bore the cylinder is found to be much less than in 
those placed horizontally, a very desirable object in a large establishment. 

A short description of its several parts will enable the reader more fully to understand the advanta- 
ges already alluded to. 

Fig. 494 represents a cross-section of tins machine, and Fig. 497 a plan showing its position in a 
corner of the building where it is placed. In these two views it will be seen that the driving part of 
the machinery is situated below the ground-line on suitably strong foundations, in which it is enclosed. 
These parts are rendered accessible by the steps t, which are found to be necessaiy in cases where the 
machinery is likely to get out of order, a precaution never to be neglected. 

The two riggers k k receive their motion from the main shaft by means of a leather strap : one of 
these runs loose on the shaft, and the strap is thrown on it when the machine is not at work ; this is 
done at pleasure with the greatest possible facility ; by a bevel-wheel and pinion /, it is then conveyed 
through the shaft i to the endless worm n, working in a large worm-wheel o, which is fixed on the great 
vertical boring-bar a, whereby a very easy motion is obtained, and all jerks avoided. It will be seen 
by the series of wheels in Fig. 497, how much the speed of the boring-bar is reduced. The shaft i 
is placed at an angle, and works in a bearing or plummer block and a step h, both of these being made 
of brass. 

The vertical bar is made in two parts a and e, the upper one a for carrying the cutter-head or boring- 
wheel r, while to the lower one is connected the driving apparatus ; they are coupled together by the 
upper one resting, as is shown in Fig. 496, in a socket on the top of the lower one ; a steel key I is 
then driven in, which entirely prevents it from turning ; the toe of the bar c rests in a step or socket 
shown by Fig. 49S ; the entire weight of this bar and its appendages is thrown on the hardened cast-steel 
disks s, which are constantly kept supplied with oiL Both extremities of the bar c are rendered ad- 
justable to the greatest possible accuracy by means of the small set-screws q q, Figs. 496 and 498, 
which, by being tightened, press against the conical brass segments, the upper one forming part of the 
great base or floor-plate b, which is materially strengthened by six strong ribs on its under side. The 
cross-beam g is well fitted to the sockets f, built into the wall of the building, where they are bolted by 
strong bolts, Figs. 494, 495, and 497. It has an additional stay in the bolt «. 

There are four standards or supports, dd, Fig. 494, for carrying the cylinder to be bored, which can 
be altered to any convenient position by unscrewing the bolts which fix theni to the base-plate. After 
the cylinder has been properly placed in its right position, it is fixed to these supports by clamps e and 
bolts ; and thus rendered quite immoveable. 

In the boring-bar a is a deep socket m, Fig. 494, which allows the bar to slide up and down by 
means of the screw p and the nut I ; upon the lower side of this socket is a flange m, upon which tln- 
cutter-head or wheel r rests, receiving its motion from the bar by means of a nut, answering both the 
purpose of nut and key. By the different arrangements of the sun and planet motion of the wheels on 
the upper part of the bar, any degree of motion can be given to the screw for the descent of the cutter- 
wheeL After the cylinder has been once bored through, the cutter-wheel is raised by means of a small 
crane, and the chains, Fig. 495, and by the peculiar arrangement of the nut I in the socket m, the cutter- 
wheel can be drawn up the cylinder without turning the screw p, as it leaves the nut behind, which is 
afterwards screwed up, there being no other weight to raise but that of the nut. The cutters are then 
set afresh to the new or finishing cut, after which the cylinder may be considered perfectly true. The 
position occupied by the crane enables the cylinder to be placed, and the bar lifted in and out with 
most perfect ease ; while the space occupied by this machine is very small compared with those where 
the work is performed horizontally ; it is, however, important that the base-plate b should be well 
secured to the foundations by strong bolts. 

Tiie speed of this machine may very easily be varied, by having different-sized riggers or pulleys on 
the driving-shaft which conveys the motion to the riggers "k k. Figs. 494 and 497. 

BORING MACHINE, Great, By Messrs. Nasmyth, Gaskell and Co. The machine represented by 
Fig. 499 is, with few exceptions, the same as that last described, where the cylinder to be bored i» 
placed in a vertical position, whereby numerous advantages are derived, as already explained. 

The motion is communicated by the driving-pulley c to a bevel pinion working the bevej wheel d : 



i Boring-bar. 

ft Foundation or base plate. 

e Socket and lower part of upright 

d Moveable supports for carrying cyl- 
inder to be bored. 

e Clamps. 

f Socket for carrying the beam g. 

<r Cmss-beam. 

h Step or bearing for driving-shaft. 
i Driving-shaft. 
j Bevel-wheel and pinion. 
k Driving riggers. 
/ Keys and nut. 
n Socket upon which the cutter-wheel 

n Screw working in wheel o. 
o Screw-wheel. 

p Screw for regulating drilling-bar. 
q Adjusting-screws. 
r Boring-wheel, 
s Steel disks or pivots. 
t Steps. 
u Tie bar. 



the shaft on which this wheel is fixed, has on its opposite end a worm for communicating the motion 
through the worm-wheel to the upright shaft/ and boring-bar a, having on its circumference the grooves 
a' in which the cutter-head is moveable, sliding up and down according to the progress of the work; 
k is a tool-carrier fixed to the cutter-head. The foundation plate h forms a bearing for the upright 
shaft, the lower end of winch rests in the step if, while the cylinder I is secured by the clamps jj to the 
supports i i fixed to the foundation plate. These parts are in every respect similar to the boring ma- 
chine shown by Fig. 494, by which they are more fully described. 

Two strong piers of masonry m' support the entablature m, (for carrying the self-acting apparatus for 
raising and lowering the cutter-head b,) to winch it is bolted by strong holding-down bolts m". This 
apparatus consists of a rack n worked by a pinion, the motion being transmitted from a trullion-wheel 
through two spur-wheels and pinions o. The whole of this upper machinery revolves with the boring- 
bar, with the exception of the internal wheel or screwed hoop p ; the consequence of which is, the small 
trullion-wheel is made to turn on its axis by the thread of the wheel p in which it works, and thereby 
ultimately raises the cutter-head b, the two side-slings connecting it to the upper frame q', to which is 
fixed the rack n. 

This machine is of the largest dimensions, and was made for the purpose of boring the large cylin- 
ders, 10 feet in diameter, for the Great Western Steam Navigation Company's vessel the Mammoth, 
tt their works at Bristol. 

T~ T 

i Upright bnrin^-bar. 

6 Cutter-head working up and down 
in the three V*s a'. 

c Driving-pulleys fixed on shaft e\ 

d Bevel-wheel and pinion for convey- 
ing the motion at right angles. 

e Worm-wheel. 

f Upright shaft for working boring-bar. 

e Step for shaft. 

7i Foundation plate and boring-box 
bearing, tightened by conical pieces 
and screws h . 

i Supports for carrying the cylinder to 

be bored. [ports i. 

j Clamps for fixing cylinder to sup- 

/; Tool-carrier fixed to cutter-head. 

/ Cylinder being bored. 

m Entablature "for guiding the upper 
part of bar, bolted to walls m' by 
bolts m". 

n Rack and pinion for raising the cut- 
ter-head, worked by spur-wheels 
and pinions a. 

o Spur-wheels and pinions. 

P Internal screw-wheel on the uppei 
part of cutter-head conveying the 
self-acting raising motion to it, by 
the trullion-wheel and spur-wheels 
and pinions o. 

q Side-slings which convey the eleva- 
ting or cut- feeding motion from the 
rack n down to the cutter-head b. 
All revolves with the boring-bar 
except the internal screw-wheel or 
screwed hoop p, which is stationa- 
ry, being bolted to the entablature. 

BORING MACHINE, Vertical. By Messrs. Benjamin Hick and Son, Bolton. By this combination 
of three distinct machines, the following different operations may be performed, viz. boring, drilling, and 
face-grinding: it is so contrived that the entablature b, supported by the four columns a a a a, carrier 


c Columns for supporting the entabla- 
b Entablature. [lure b. 

c Boring-bar of large machine. 
d Driving-pulleys worked by leather 

strap d'. 
e Bevel-wheel and pinion conveying 

the motion to the upright shaft / 

through the column a. 
f rprk'ht shaft working in footstep t". 
tr Spur pinion and wheel for working 

the boring-bar c. 

to be bored moveable in grooves 
in the foundation plate n. 

i Clamps or Caps for securing the cyl- 
inder to the supports h. 

j Circular frame or ring for steadying 
the cylinder, which is adjusted to 
its proper place by the set-screws.?': 
this frame can be raised or lowered, 
and is secured by bolts fitted into 
grooves in the back of columns a, 

k Racks and wheels attached to the 
boring-block u-ontaining the steel 

cutters) for giving it the feed or 
advancing motion. 

I Second floor of the building, and on 
which is placed a crane for raising 
or lowering the boring-bar when a 
cylinder has to be placed or re- 
mo ved. 

m Footstep for boring-bar. 

?i Foundation plate. 

o Framing and beds of the side ma- 
chines on which the V slides o* 

travelling tables for carrying the 
work to be bored, &c. 

, Driving-pulleys for machines B and 
C, worked by straps a'. 

r Cross-shaft, levels, and links, for oc- 
casionally raising the grinding-plate 
r', of machine C. 

*■ Cross-frame lor carrying the brackets 
s' s' for supporting the shaft r. 

t Guide-frame for boring-bar of ma- 
chine B, fixed between the two 
columns a a. 

i Reversed, cones, strap-shaft, and bev- 
el-wheels, for giving the feeding 
motion to the upright boring-bar u 
by means of the screw u" attached 
to its upper ond. The shaft is sup- 

ported by the two bracket car- 
riages u'" u"'. 

v Chain pulleys and weight for raising 
the boring-bar u supported by th ■ 
two brackets v' v'. 

w Cylinder being bored. 

x Crank being bored. 

y Piston having its face ground: 



the upper parts of the three different machines, consisting of the requisite driving machinery for com- 
municating to them their' respective motions. 

That in the centre, A, is a vertical boring machine for boring cylinders of large diameters, which are 
fixed in the usual way on the six moveable supports h by the clamps i ; in addition to which it is ren- 
dered perfectly steady by the circular frame or ringj, sliding up and down in grooves on the back of 
the two middle columns, the adjusting-screws j being tightened when the cylinder is properly placed 
under the centre of the boring-bar c, which receives its motion from the leather strap and pulleys d, 
whence it is conveyed through the bevel pinion and wheel e on the upright shaft f, upon which is also 
keyed the spur-pinion for driving the wheel g fixed to the lower part of the boring-bar c, and working 
in the step m ; the rack and wheel k gives the cutter-head the requisite feed wliile boring out the 
cylinder. The six supports h are made to slide in grooves on the foundation plate n, according to the 
different diameters of the cylinders being operated upon ; these, when properly placed, are bolted to 
the plate 71. 

The second machine, B, is a vertical drilling and boring macliine for work of smaller dimensions than 
the machine A. It is shown in the drawing boring out the centre of a crank x, fixed to the travelling 
table p, and slides on Y's on the frame o', which has also a motion at right angles, on the bed o fixed 
to the foundation plate. The drilling-bar u' is lowered by the screw u" according to the feed, its mo- 
tion being conveyed to it from the pulley q and strap q' to a spur-wheel and pinion not shown in the 
drawing ; the pinion is on the same spindle as the pulley, and the wheel on that of the reversed cone u, 
by which it is carried to the square-threaded screw u" by two pairs of small bevel-wheels u, fixed on 
a horizontal spindle and working in suitable bearings on the carnages u'" is'". The apparatus for 
raising the drilling-bar, Fig. 500, consists simply of two small chains fixed to the bar u' and working 
round the pulleys, its opposite end being attached to a weight v. 

The third machine C, is for the purpose of grinding up the faces of rings for metallic pistons, conical 
valves, <to. ; the travelling table p of this machine is in every respect similar to that of B, and upon it is 
placed the piston y to be ground ; the upright rod, receiving its motion from the pulley and strap q', is 
kept in a vertical position by the cross-frame s, while the shaft r and grinding-plate are connected to 
the lower end of the rod, and are occasionally raised for examining the surface being ground. 

The different motions given to these machines are quite independent the one of the other, by which 
means any one of them can be worked separately. The whole is placed on a suitable strong founda- 
tion of stone. After the large cylinder is bored, it is raised from its position by a crane placed on the 
floor above. 

BORING MACHINES, for cannon. See Cannon. 

BORING FOR WELLS, and Tools therefor. See Artesian Wells. 

BORIXG TOOLS.* The process of boring holes may be viewed as an inversion of that of turning ; 
generally the work remains at rest, and the tool is revolved and advanced. Many of the boring and 
drilling tools have angular points, which serve alike for the removal of the material, and the guidance 
of the instrument ; others have blunt guides of various kinds for directing them, whilst the cutting is 
performed by the end of the tool 

Commencing as usual with the tools for wood, the brad-awl, Fig. 502, may be noticed as the most 
simple of its kind ; it is a cylindrical wire with a chisel edge, which rather displaces than removes the 
material ; it is sometimes sharpened with three facets as a triangular prism. The awl, Fig. 503, used 
by the wire-workers, is less disposed to split the wood ; it is square and sharp on all four edges, and 
tapers off very gradually until Dear the point, where the sides meet rather more abruptly. 

The generality of the boring instruments used in carpentry are fluted, like reeds split in two parts, 
to give room for the shavings, and they are sharpened in various ways, as shown by Figs. 504 to 508. 
Fig. 504 is known as the shell-bit, and also as the 

gouge-bit, or quill-bit ; it is sharpened at the end like 502. 503. 504. 505. 506. 507. 508. 

a gouge, and when revolved it shears the fibres 
around the margin of the hole, and removes the 
wood almost as a solid core. The shell-bits are in 
very general use, and when made very small, they 
are used for boring the holes in some brushes. 

Fig. 505, the spoon-bit, is generally bent up at 
the end to make a taper point, terminating on the 
diametrical line ; it acts something after the manner 
of a common pointed drill, except that it possesses 
the keen edge suitable for wood. The spoon-bit is 
in very common use ; the coopers dowel-bit, and the 
table-bit, for making the holes for the wooden joints 
of tables, are of this kind. Occasionally the end is 
bent in a semicircular form ■, such are called duek- 
nose-bits from their resemblance, and also brush- 
bits from their use ; the diameter of the hole con- 
tinues undiminished for a greater depth than with the pointed spoon-bit. 

The nose-bit, Fig. 506, called also the slit-nose-bit, and auger-bit, is slit up a small distance near the 
centre, and the larger piece of the end is then bent up nearly at right angles to the shaft, so as to act 
like a paring-chisel ; and the corner of the reed, near the nose, also cuts slightly. The form of the 
nose-bit, which is very nearly a dimin utive of the shell-auger, Fig. 507, is better seen in the latter 
instrument, in wh/ch the transverse cutter lies still more nearly at right angles, and is distinctly curved 
on the edge instead of radiaL The augers are eoEietimes made three inches diameter, and upwards, 

Holtzapffel's Turning and Mechanical Manipulation, 



and with long removeable shanks, for the purpose of boring wooden pump-barrels ; they are then called 

^There is some little uncertainty of the nose-bits entering exactly at any required spot unless a 
small commencement ii previously made with another instrument, as a spoon-bit, a gouge, a brad-awL 
a centre-punch or some other tool ; with augers a preparatory hole is invariably made, either with a 
gouo-e or with a centre-bit exactly of the size of the auger. When the nose-bits are used for making 
the holes in sash bars, for the wooden pins or dowels, the bit is made exactly parallel, and it has a 
square brass socket which fits the bit; so that the work and socket being fixed in their respective 
situations,' the guide-principle is perfectly applied. A "guide-tube" built up as a tripod, which the 
workman steadies with his foot, has been recently applied by Mr. Charles May, of Ipswich, tor boring 
the auger-holes in railway sleepers exactly perpendicular. . _ 

The o-imlet, Fig. 508, is also a fluted tool, but it terminates in a sharp worm or screw, beginning as a 
point and extending to the full diameter of the tool, which is drawn by the screw into the wood. The 
principal part of the cutting is done by the angular corner intermediate between the worm and shell, 
which acts much like the auger. The gimlet is worked until the shell is full of wood, when it is unwound 
and withdrawn to empty it. ... ., 

The centre-bit, Fig. 509, shown in three views, is a very beautiful instrument ; it consists ot three 
parts, a centre-point or pin, filed triangularly, which serves as a guide for position ; a thin shearing- 
point or nicker, that cuts through the fibres like the point of a knife; and a broad .chisel-edge or cutter, 
placed obliquely to pare up the wood within the circle marked out by the point. The cutter should 
have both a little less radius and less length than the nicker, upon the keen edge of which last the 
correct action of the tool principally depends. 

Many variations are made from the ordinary centre-bit, Fig. 509. 510. 

509 ; sometimes the centre-point is enlarged into a stout cylin- 
drical plug, so that it may exactly fill a hole previously made, 
and cut out a cylindrical countersink around the same, as for 
the head of a screw-bolt. This tool, known as the plug centre- 
bit, is much used in making frames and furniture, held together 
by screw-bolts. Similar tools, but with loose cutters inserted 
in a diametrical mortise, in a stout shaft, are also used in ship- 
building for inlaying the heads of bolts and washers, in the 
timbers and planking. 

The wine-cooper's centre-bit is very short, and is enlarged 
behind into a cone, so that immediately a full cask has been 
bored, the cone plugs up the hole until the tap is inserted. The 
centre-bit deprived of its chisel-edge, or possessing only the pin 
and nicker, is called a button-tool ; it is used for boring and 
cutting out, at one process, the little leather disks or buttons, 

which serve as nuts for the screwed wires in the mechanism connected with the keys of the organ and 

The expanding centre-bit, shown on a much smaller scale in Fig. 512, is a very useful instrument; it 
has a central stem with a conical point, and across the end of the stem is fitted a transverse bar 
adjustable for radius. When the latter carries only a lancet-shaped cutter it is 
used for making the margins of circular recesses, and also for cutting out disks of 
wood and thin materials generally ; when, as in Mr. James Stone's modification, the 
expanding centre-bit has two shearing-points or nickers, and one chisel-formed 
cutter, it serves for making grooves for inlaying rings of metal or wood in cabinet- 
work, and other purposes. 

The above tools being generally used for woods of the softer kinds, and the 
plankway of the grain, the shearing-point and oblique chisel of the centre-bit, Fig. 
509, are constantly retained, but the corresponding tools used for the hard woods 
assume the characters of the hard-wood tools generally. For instance, a, Fig. 510, 
has a square point, also two cutting edges, which are nearly diametrical, and sharpened with a single 
chamfer at about 60 degrees; this is the ordinary drill used for boring the finger-holes in flutes and 
clarionets, which are afterwards chamfered on the inner side with a stout knife, the edge of which 
measures about 50 degrees. The key-holes are first scored with the cup-keg tool, b, and then drilled, 
the tools a and 6 being represented of corresponding sizes, and forming between them the annular 
ridge which indents the leather of the valve or key. 

When n, Fig. 510, is made exactly parallel and sharpened up the sides, it cuts hard mahogany very 
cleanly in all directions of the grain, and is used for drilling the various holes in the small machinery of 
pianofortes ; this drill (and also the last two) is put in motion in the lathe; and in Fig. 511, the lathe- 
drill for hard woods, called by the French langue de carpe, the centre-point and the two sides melt into 
an easy curve, which is sharpened all the way round and a little beyond its largest part. 

Various tools for boring wood have been made with spiral stems, in order that the shavings may be 
enabled to ascend the hollow worm, and thereby save the trouble of so frequently withdrawing the bit. 
For example, the shaft of Fig. 513, the single-lip auger, is forged as a half-round bar, nearly as in the 
section above ; it is then coiled into an open spiral with the flat side outwards, to constitute the cylin- 
drical surface, and the end is formed almost the same as that of the shell-auger, Fig. 507. The twisted 
gimlet, Fig. 514, is made with a conical shaft, around which is filed a half-round groove, the one edge of 
which becomes thereby sharpened, so as gradually to enlarge the hole after the first penetration of the 
worm, which, from being smaller than in the common gimlet, acts with less risk of splitting. 

The ordinary screw-auger, Fig. 515, is forged as a parallel blade of steel, (seen in Fig. 516, which 
also refers to 515 and 517 it is twisted red-hot, the end terminates in a worm bv which the auger is 



gradually drawn iuto the work, as iu the gimlet, and the two angles or lips are sharpened to cut at the 
extreme ends, and a little up the sides also. 

The same kind of shaft is sometimes made as in Fig. 516, with a plain conical point, with two scoring 
cutters and two chisel edges, which receive their obliquity from the slope of the worm : it is as it were 
a double centre-bit, or one with two lips grafted on a spiral shaft. The same shaft has been also made, 
<i° in Fig. 517, with a common drill-point, and proposed for metal, but this seems scarcely called for ; 

but it is in this form very effective in Hunter's patent stone-boring machine, intended for stones not 
harder than sandstones ; the drill is worked by a cross, guided by a tube, and forced in by a screw cut 
upon the shaft carrying the drill ; so that the stone is not ground to powder, but cast off in flakes with 
very little injury to the drill. 

Another screw-auger, which is perhaps the most general after the double-lipped screw-auger, Fig 
515, is known as the American screw-auger, and is shown in Fig. 518 ; this has a cylindrical shaft, 
around which is brazed a single fin or rib ; the end is filed into a worm as usual, and immediately be- 
hind the worm a small diametrical mortise is formed for the reception of a detached cutter, which ex- 
actly resembles the nicking-point and chisel-edge of the centre-bit ; it may be called a centre-bit for 
deep holes. The parts are shown detached in Fig. 519. The loose cutter is kept central by its square 
notch, embracing the central shaft of the auger ; it is fixed by a wedge driven in behind, anil the 
chisel-edge rests against the spiral worm. Spare cutters are added in case of accident, and should the 
screw be broken off, a new screw and mortise may be made by depriving the instrument of so much 
of its length. This instrument will be found on trial extremely effective ; and on account of the great 
space allowed for the shavings, they are delivered perfectly, until the worm is buried a small distance 
beneath the surface of the hole. 

The Americans have also invented an auger, thoroughlv applicable to producing square holes, and 
those of other forms : the tool consists of a steel tube, of the width of the hole, the end of the tube is 
sharpened from within, with the corners in advance, or with four hollowed edges. In the centre of the 
square tube works a screw-auger, the thread of wliich projects a little beyond the end of the tube, so 
as first to penetrate the wood, and then to drag after it the sheath, and thus complete the hole at one 

f>rocess ; the removed shavings making their escape up the worm and through the tube. For boring 
ong mortises, two or more square augers are to be placed side by side, but they must necessarily be 
worked one at a time. The tools Figs. 513 to 520 are American. 

The screw-auger acts as a hollow taper-bit or rimmer, and the screw-form point and shaft 
assist in drawing it into the wood ; but the instrument must pass entirely through for making cylin- 
drical holes. 

The most usual of the modes of giving motion to the various kinds of boring bits, is by the ordinary- 
carpenter's brace with a crank-formed shaft. The instrument is made in wood or metaL and at the one 
extremity has a metal socket called the pad, with a taper square hole, and a spring catch used for 
retaining the drills in the brace when they are withdrawn from the work ; and at the other it has a swiv- 
elled head or shield, which is pressed forward horizontally by the chest of the workman ; or when used 
vertically, by the left hand, which is then commonly placed 
against the forehead. 

The ordinary carpenter's brace is too familiarly known to 
require further description, but it sometimes happens, that in 
corners and other places there is not room to swing round the 
handle; the angle brace, Fig. 521, is then convenient. It is 
made entirely of metal, with a pair of bevel pinions, and a 
winch-handle that is placed on the axis of one of these, at 
various distances from the centre, according to the power or 
velocity required. Sometimes the bevel-wheel attached to 
the winch handle is three or four times the diameter of 
the pinion on the drill; this gives greater speed, but less 



The augers, -which from their increased size require more power, are moved by transverse handles 
some augers are made with shanks, and are riveted into the handles just like the gimlet ; occasionally 
the handle has a socket or pad, for receiving several augers, but the most common mode is to form the 
end of the shaft into a ring or eye, through which the transverse handle is tightly driven. The brad- 
awls, and occasionally the other tools requiring but slight force, are fitted in straight handles ; many 01 
the smaller tools are attached to the lathe-mandrel by means of chucks, and the work is pressed against 
them, either by the hand, or by a screw, a slide, or other contrivance; Figs. 510 and 511 are always 
thus applied. 

Drills for metal, used by hand. — The frequent necessity in metal works, for the operation of drilling 
holes, wliich are required of all sizes and various degrees of accuracy, has led to so very great a variety 
of modes of performing the process, that it is difficult to arrange with much order the more important 
of these methods and apparatus. 

The ordinary piercing drills for metal do not present quite so much variety as the wood drills re- 
cently described. The drills for metal are mostly pointed ; they consequently make conical holes, whiei 
cause the point of the drill to pursue the original line, and eventually to produce the cylindrical hole. 
The comparative feebleness of the drill-bow limits the size of the drills employed with it to about one- 
quarter of an inch in diameter ; but as some of the tools used with the bow, agree in kind with those 
of much larger dimensions, it will be convenient to consider as one group, the forms of the edges of those 
drills which cut when moved in cither direction. 

Figs. 522, 523, and 524, represent, of their largest sizes, the usual forms of drills proper for the re- 
ciprocating motion of the drill-bow, because their cutting edges being situated on the line of the axis, 
and chamfered on each side, they cut, or rather scrape, with equal facility in both directions of motion. 

Fig. 522 is the ordinary double-cutting drill ; the two facets forming each edge meet at an angle of 
about 50 to 70 degrees, and the two edges forming the point meet at about 80 to 100 ; but the watch- 
makers, who constantly employ this kind of drill, sometimes make the end as obtuse as an angle of 
about 1 20 degrees ; the point does not then protrude through their thin works, long before the comple- 
tion of the hole. Fig. 523, with two circular chamfers, bores cast-iron more rapidly than any other re- 
ciprocating drill, but it requires an entry to be first made with a pointed drill ; by some, this kind is also 
preferred for wrought-iron and steeb The flat-ended drill, Fig. 524, is used for flattening the bottoms 
of holes. Fig. 525 is a duplex expanding drill, used by the cutlers for inlaying the little plates of metal 
in knife-handles; the ends are drawn full size. 

Fig. 526 is also a double-cutting drill ; the cylindrical wire is riled to the diametrical line, and the end 
is formed with two facets. This tool has the advantage of retaining th; same diameter when it is sharp- 
ened ; it is sometimes called the Swiss drill, and was employed by II. Le Riviere, for making the nu- 
merous small holes in the delicate punching machinery for manufacturing perforated sheets of metal 
and pasteboard ; these drills are sometimes made either semicircular or flat at the extremity, and as 
they are commonly employed in the lathe, they will be hereafter further noticed. 

The square countersink, Fig. 527, is also used with the drill-bow ; it is made cylindrical, and pierced 
for the reception of a small central pin, after which it is sharpened to a chisel-edge, as shown. This 
countersink is in some measure a diminutive of the pin-drills, Figs. 534 to 537, and occasionally circular 
collars are fitted on the pin for its temporary enlargement, or around the larger part to serve as a stop, 
and limit the depth to which the countersink is allowed to penetrate, for inlaying the heads of screws. 
The pin is removed when the instrument is sharpened. 

By way of comparison with the double-cutting drills, the ordinary forms of those which only cut in 
one direction, are shown in Figs. 52S, 529, and 530. Fig. 528 is the common single-cutting drill, for the 
chill-bow, brace, and lathe ; the point, as usual, is nearly a rectangle, but is formed by only two facets, 
which meet the sides at about 80° to 85° ; and therefore lie veiy nearly in contact with the extremity 
of the hole operated upon, thus strictly agreeing with the form of the turning tools for brass. Fig. 529 
is a similar drill, particularly suitable for horn, tortoise-shell, and substances liable to agglutinate and 
clog the drill; the chamfers are rather more acute, and are continued around the edge behind its largest 
diameter, so that if needful, the drill may also cut its way out of the hole. 

Fig. 530, although never used with the drill-bow, nor of so small a size as in the wood-cut, is added 
to show how completely the drill proper for iron, follows the character of the turning tools for that 
metal ; the flute or hollow filed behind the edge, gives the hook-formed acute edge required in this tool, 
which is in other respects like Fig. 528 ; the form proper for the cutting edge is showr. more distinctly 
in the diagram a, Fig. 534. 

BORING tools. 


Care should always be taken to hare a proportional degree of strength in the shafts of the drills, 
otherwise they tremble and chatter when at work, or they occasionally twist off in the neck ; the point 
should be also ground exactly central, so that both edges may be cut. As a guide for the proportional 
thickness of the point, it may measure at b, Fig. 531, the base of the cone, about one-fifth the diameter 
of the hole ; and atp, the point, about one-eighth, for easier penetration: but the fluted drills are made 
nearly of the same thickness at the point and base. 

In all the drills previously described, except Fig. 526, the size of the point is lessened each time of 
harpening ; but to avoid tliis loss of size, a small part is often made parallel, as shown in Fig. 531 In 
Fig. 532, this mode is extended by making the drill with a cylindrical lump, so as to fill the hole; this 
is called the recentering-drill. It is used for commencing a small hole in a flat-bottomed cylindrical 
cavity ; or else, in rotation with the common piercing-drill, and the half-round bit, in drilling small and 
very deep holes in the lathe. Fig. 532 may be also considered to resemble the stop-drill, upon winch 
a solid lump or shoulder is formed, or a collar is temporarily attached by a side-screw, for limiting the 
depth to which the tool can penetrate the work. 

Fig. 533, the cone countersink, may be viewed as a multiplication of the common single-cutting drill 
Sometimes, however, the tool is filed witli four equidistant radial furrows, directly upon the axis, and 
with several intermediate parallel furrows sweeping at an angle around the cone. This makes a more 
even distribution of the teeth than when all are radial as in the figure, and it is always used in the 
spherical cutters or countersinks known as cherries, which are used in making bullet-moulds. 

On comparison, it may be said, the single-chamfered drill, Fig. 528, cuts more quickly than the doub'.p- 
chamfered, Fig. 522, but that the former is also more disposed of the two to swerve or run from its 
intended position. In using the double-cutting drills, it is also necessary to drill the holes at once to 
their full sizes, as otherwise the thin edges of these tools stick abruptly into the metal, and are liabl' 

to produce jagged or groovy surfaces, which destroy the circularity of the holes • the necessity for drill- 
ing the entire hole at once, joined to the feebleness of the drill-bow, limits the size of these drills. 

In using the single-chamfered drills it is customary, and on several accounts desirable, to make large 
holes by a series of two or more thills ; first the run of the drill is in a measure proportioned to its 
diameter, therefore the small tool departs less from its intended path, and a central hole once obtained, 
it is followed, with little after-risk, by the single-cutting drill, which is less penetrative. This mode 
likewise throws out of action the less favorable part of the drill near the point, and which in large drills 
is necessarily thick and obtuse ; the subdivision of the work enables a comparatively small power to be 
used for drilling large holes, and also presents the choice of the velocity best suited to each progressive 
diameter operated upon. But where sufficient power can be obtained, it is generally more judicious tc 
enlarge the holes previously made with the pointed-drills, by some of the group of pin-drills. Figs. 53-1 
to 537, in which the guide-principle is very perfectly employed : they present a close analogy to the 
plug centre-bit and the expanding centre bit used in carpentry. 

The ordinary pin-drill, Fig. 534, is employed for making countersinks for the heads of screw-bolts in 
laid flush with the surface, and also for enlarging holes commenced with pointed drills, by a cut parallel 
fritli the surface ; the pin-drill is also particularly suited to thin materials, as th» point of the ordinary 


drill would soon pierce through, and leave the guidance less certain. When this tool is used for iron it 
is fluted as usual and a represents the form of the one edge separately. 

Fig. 535 is a pin-drilL principally used for cutting out large holes in cast-iron and other plates. In 
this case the narrow cutter removes a ring of metal, which is, of course, a less laborious process than 
cutting the hole into shavings. When this drill is applied from, both sides it may be used for plates 
half aii inch and upwards in thickness ; as, should not the tool penetrate the whole of the way through, 
the piece may be broken out, and the rough edges cleaned with a file or a broach. 

Fi". 536 is a tool commonly used for drilling the tube-plates for receiving the tubes of locomotive- 
boilers: the material is about \ inch thick, and the holes 1} diameter. The loose cutter a is fitted in a 
transverse mortise, and secured by a wedge ; it admits of being several times ground before the notch 
which o-uiilcs the blade for centrality is obliterated. Fig. 537 is somewhat similar to the last two, but 
is principally intended for sinking grooves ; and when the tool is figured, as shown by the dotted line, 
it mav be used for cutting bosses and mouldings on parts of work not otherwise accessible. 

Many ingenious contrivances have been made to insure the dimensions and angles of tools being ex- 
actly retained. In tin's class may be placed Sir. Roberts' pin-drill, Figs. 538 and 539 ; in action it re- 
sembles the fluted pin-drill, Fig. 534, _ « 
but the iron stock is much heavier, and °' JS - /^ _EL 539 - 

is attached to the drilling-machine by jf 7^ /T n X ^ =^*\ a 

Ihe q are tang; the stock has two / /""fjJs^X tT ^"A \ y^Sl|115|^\ ..,A3ijg 

grooves at an angle of about 10 '!<■- __ I J/ZT-YtL'! -] £-}- \) ' r~M j. ]; .. b.-j .- ^ — 

grees with the axis, and rather deeper \:\fSry l~vt^^i j j _L-*J&- "T '"/ 

behind than in front. Two steel cut- \^&^ J \^7"/^\ J J 

ters, or nearly parallel blades, repre- Xj. S \^_-/ V_«i_/ 

sented black, are laid in the groves ; ^ ■* 

they are fixed by the ring and two set- 
screws z s, and are advanced, as they become worn away, by two adjusting-screws a a, (only one seen,) 
placed at the angle of 10 degrees through the second rmg ; which, for the convenience of construction, 
is screwed upon the drill-shaft just beyond the square tang whereby it is attached to the drilling- 
machine. The cutters are ground at the extreme ends, but they also require an occasional touch on the 
oilstone to restore the keenness of the outer angles, which become somewhat rounded by the friction. 
The diminution from the trifling exterior sharpening, is allowed for by the slightly taper form of the 

The process of drilling generally gives rise to more friction than that of turning, and the same meth- 
ods of lubrication are used, but rather more commonly and plentifully ; thus oil is used for the generality 
of metals — or from economy, soap and water ; milk is the most proper for copper, gold, and silver ; and 
cast-iron and brass are usually drilled without lubrication. For all the above-named metals, and for 
alloys of similar degrees of hardness, the common-pointed steel thills are generally used ; but for lead 
and very soft alloys, the carpenters' spoon-bits and nose-bits are usually employed, with water. For 
hardened steel, and hard crystalline substances, copper or soft-iron drills, such as Figs. 529 or 530, sup- 
plied with emery-powder and oil, are needed; or the diamond drill-points, Figs. 531, 532, and 533, are 
used for hardened steel, with oil alone. 

Having considered the most general forms of the cutting parts of drills, we will proceed to explain 
the modes in which they are put in action by hand-power, beginning with those for the smallest diame- 
ters, and proceeding gradually to the largest. 

Methods of Working Drills hy Hand-power The smallest holes are those required in watch-work, 

and the general form of the drill is shown on a large scale in Fig. 540 ; it is made of a piece of steel 

wire, which is tapered off at the one end, 

flattened with the hammer, and then filed 

up in the form shown at large in Fig. 522 ■ — <^ 

lastly, it is hardened in the candle. The 

re ;'trse end of the instrument is made into 

a conical point, and is also hardened ; near this end is attached a little brass sheave for the line of the 

drill-bow, which, in watchmaking, is sometimes a fine horsehair, stretched by a piece of whalebone of 

about the size of a goose's quill stripped of its feather. 

The watchmaker holds most of his works in the fingers, both for fear of crushing them with the 
table-vice, and also that he may the more sensibly feel his operations ; drilling is likewise performed 
by him in the same manner. Having passed the bowstring around the pulley in a single loop, (or with 
a round turn,) the centre of the drill is inserted in one of the small centre-holes in the sides of the table- 
vice, and the point of the drill is placed in the mark or cavity made in the work by the centre-punch ; 
the object is then pressed forward with the right hand, whilst the bow is moved with the left. 

Clockmakers, and artisans in works of similar scale, fix the object in the tail-vice, and use drills, such 
as Fig. 540, but often larger and longer; they are pressed forward by the chest, which is defended from 
injury by the breastplate, namely, a piece of wood or metal about the size of the hand, in the middle 
of which is a plate of steel, with centre-holes for the drill. The breastplate is sometimes strapped 
round the waist, but is more usually supported with the left hand, the fingers of which are ready to 
catch the drill should it accidentally slip out of the centre. 

As the drill gets larger the bow is proportionably increased in stiffness, and eventually becomes the 
half of a solid cone, about one inch in diameter at the larger end, and 30 inches long ; the catgut 
string is sometimes nearly an eighth of an inch in diameter, or r replaced by a leather thong. The 
string is attached to the smaller end of the bow by a loop and notch, much the same as in the archery- 
bow, and is passed through a hole at the larger end, and made fast with a knot ; the surplus length is 
wound round the cane, and the cord finally passes through a notch at the end, wliicb prevents it from 



Steel bows are also occasionally used; these are made something like a fencing-foil, but with a hook 
at the end for the knot or loop of the cord, and with a ferrule or a ratchet, around which the spare cord 
is wound. Some variations also are made in the sheaves of the large drills ; sometimes they are cylin- 
drical with a fillet at each end ; this is desirable, as Jie cord necessarily lies on the sheave at an angle, 
ir> fact in the path of a screw ; it pursues that path, and with the reciprocation of the drill-bow the 
cord traverses, or screws backwards and forwards upon the sheave, but is prevented from sliding off by 
the fillet. Occasionally, indeed, the cylindrical sheave is cut with a screw coarse enough to receive the 
cord, which may then make three or four coils for increased purchase, and have its natural screw-like 
run without any fretting whatever; but this is only desirable when the holes are large and the drill is 
almost constantly used, as it is tedious to wind on the cord for each individual hole. The structure of 
the bows, breastplates, and pulleys, although oiten varied, is sufficiently familiar to be understood 
without figures. 

When the shaft of the drill is moderately long, the workman can readily observe if the drill is square 
with the work as regards the horizontal plane; and to remove the necessity for the observation of an 
assistant as to the vertical plane, a trifling weight is sometimes suspended from the drill-shaft by a 
metal ring or hook ; the joggling motion shifts the weight to the lower extremity : the tool is only hori- 
zontal when the weight remains central. 

In many cases, the necessity for repeating the shaft and pulley of the drill is avoided, by the em- 
ployment of holders of various kinds, or drill-slocks, which serve to carry any required number of drill- 
points. The most simple of the drill- 
stocks is shown in Fig. 541 ; it has 
the centre and pulley of the ordinary 
drill, but the opposite end is pierced 
with a nearly cylindrical hole, just at 
the inner extremity of which a dia- 
metrical notch is filed. The drill is 
shown separately at a ; its shank is 
made cylindrical, or exactly to fit the 
hole, and a short portion is nicked 
down also to the diametrical line, so 
as to slide into the gap in the drill-stock, by which the drill is prevented from revolving ; the end serves 
also as an abutment whereby it may be thrust out witli a lever. Sometimes a diametrical transverse 
mortise, narrower than the hole, is made through the drill-stock, and the drill is nicked in on both sides ; 
the cylindrical hole of 541, should be continued to the bottom of the notch, the end of the drill should 
be filed off obliquely, and it should be prevented from rotating, by a pin inserted through the cylindri- 
cal hole parallel with the notch ; the taper end of the drill would then wedge fast beneath the pin. 

Drills are also frequently used in the drilling-lathe ; this is a miniature lathe-head, the frame of 
which is fixed in the table-vice ; the mandrel is pierced for the drills, and has a pulley for the bow, 
therein resembling Fig. 542, except that it is used as a fixture. 

The Fig. 542 just referred to, represents one variety of another common form of the drill stock, ia 
which the revolving spindle is fitted in a handle, so that it may be held in any position, without the 
necessity for the breastplate ; the handle is hollowed out to serve for containing the drills, and is fluted 
to assist the grasp. 

Fig. 543 represents the socket of 
a " universal drill-stock" invented 
by Sir John Robinson ; it is pierced 
with a hole as large as the largest 
of the wires of which the drills are 
formed, and the hole terminates hi 
an acute hollow cone. The end of 
the drill-stock is tapped with two 
holes, placed on a diameter; the 

one screw, a, is of a very fine thread, ;j ^TEgj^-gj-UJji - 

and lias at the end two shallow ° •-;■■,_ v-:vT7 

diamefrica 1 notches ; the other, b, is ' ^Ij-U 

of a coarser thread and quite flat at 

the extremity. The wire-drill is 

placed against the bottom of the 

hole, and allowed to lean against the adjusting-screw a, and if the drill be not central, this screw is 

moved one or several quarter-tums, until it is adjusted for centrality ; after which the tool :e strongly 

fixed by the plain set-screw b. 

Fig. 544 is a drill-stock, contrived by Jlr. William Allen : it consists of a tube, the one end of which 
has a fixed centre and pulley much the same as usual ; the opposite end of the tube has a piece of steel 
fixed into it, which is first chilled with a central hole, and then turned as a conical screw, to which is 
fitted a corresponding screw-nut n ; the socket is then sawn down with two diametrical notches, to 
make four internal angles, and lastly, the socket is hardened. When the four sections are compressed 
by the nut, their edges stick into the drill and retain it fast, and provided the instrument 13 itself con- 
centric, and the four parts are of equal strength, the centrality of the drill is at once ensured. The out- 
side of the nut, and the square hole in the key /■, are each taper, for more ready application ; and the 
drills are of the most simple kind, namely, lengths of wire pointed at each end, as in Fig. 545. 

The sketch, Fig. 544, is also intended to explain another useful application of this drill-stock, as an up- 
right or pump drill, a tool little employed in this country, (except in drilling the rivet-holes for mending 
china and glass, with diamond drill,) but as well known among the oriental nations as the breast-drill. 




Holes that are too large to be drilled solely by the breast-drill and drill-bow, are frequently com- 
menced with those useful instruments, and are then enlarged by means of the hand-brace, which is very 
similar to that used in carpentry, except that it is more commonly made of iron instead of wood, is 
somewhat larger, and generally made without the spring-catch. 

Holes may be extended to about half an inch diameter, with the hand-brace ; but it is much more 
expeditious to employ still larger and stronger braces, and to press them into the work in various ways 
by weights, levers, and screws, instead of by the muscular effort alone. 

Fig. 546 represents the old smith's press-drill, which although cumbrous, and much less used than 
formerly, is nevertheless simple and effective. It consists of two pairs of wooden standards, between 
which works the beam a b ; the pin near a is placed at any height, but the weight w is not usually 
changed, as the greater or less pressure for large and small drills, is obtained by placing the brace more 
or less near to the fulcrum a ; and this part of the beam is shod with an iron plate, full of small centre- 
holes for the brace. The weight is raised by the second lever c d, the two being united by a chain, and 
a light chain or rope is also suspended from d, to be within reach of the one or two men engaged in 
moving the brace. It is necessary to relieve the weight when the drill is nearly through the hole, 
otherwise it might suddenly break through, and the drill becoming fixed, might be twisted off in the 


The inconveniences in this machine are, that the upper point of the brace moves in an arc instead of 
a right line ; the limited path when strong pressures are used, which makes it necessaiy to shift the 
fulcrum a ; and also the necessity for readjusting the work under the drill for each different hole, 
which in awkwardly-shaped pieces is often troublesome. 

A portable contrivance of similar date, is an iron bow-frame or clamp, shown in Fig. 54*7 ; the pressure 
i s applied by a screw, but in almost all cases, wliilst the one individual drills the hole, the assistance of 
another is required to hold the frame ; Fig. 547 only applies to comparatively thin parallel works, and does 
not present the necessary choice of position. Another tool of this kind, used for boring the side-holes 
in cast-iron pipes for water and gas, is doubtless familiarly known ; the cramp or frame divides into 
two branches about two feet apart, and these terminate like hooks, winch loosely embrace the pipe, so 
that the tool retains its position without constraint, and it may be used with great facility by one 

Fig. 548 will serve to show the general character of various con- 
structions of more modern apparatus, to be used for supplying the 
pressure in drilling holes with hand-braces. It consists of a cylin- 
drical bar a, upon which the horizontal rectangular rod 6 is fitted 
with a socket, so that it may be fixed at any height, or in any 
angular position, by the set-screw c. Upon b slides a socket, which 
is fixed at all distances from a, by its set-screw d; and lastly, tliis 
socket has a long vertical screw c, by which the brace is thrust into 
the work. 

The object to be drilled having been placed level, either upon the 
ground, on trestles, on the work-bench, or in the vice, according to 
circumstances, the screws c and d are loosened, and the brace is put 
in position for work. The perpendicularity of the brace is then 
examined with a plumb-line, applied in two positions, (the eye 
being first directed as it were along the north and south line, and 
then along the east and west,) after which the whole is made fast 
by the screws c and d. The one hole having been drilled, the 
socket and screws present great facility in readjusting the instru- 
ment for subsequent holes, without the necessity for shifting the 
work, which would generally be attended with more trouble than 
altering the drill-frame by its screws. 

Sometimes the rod a is rectangular, and extends from the floor 
to the ceiling ; it then traverses in fixed sockets, the lower of which 
has a set-screw for retaining any required position. In the tool 
represented, the rod a terminates in a cast-iron base, by -which it 
may be grasped in the tail-vice, or when required it may be fixed 
upon the bench. In this case the nut on a is unscrewed ; the cast-iron plate, when reversed and pbcea 
on the bench, serves as a pedestal ; the stem is passed through a hole in the bench, and the nut and 



■washer, -when screwed on the stem beneath, secure all very strongly together. Even in establishments 
•where the most complete drilling machines driven by power are at hand, modifications of the press-drill 
are among the indispensable tools : many are contrived with screws and clamps, by 'which they aro 
attached directly to such 'works as are sufficiently large and massive to serve as a foundation. 

Various useful drilling tools for engineering works, are fitted with left-hand screws, the unwinding 
of which elongate the tools ; so that for these instruments which supply their own pressure, it is only 
necessary to find a solid support for the centre. They apply very readily in drilling holes within boxes 
and panels, and the abutment is often similarly provided by projecting parts of the castings ; or other- 
wise the fixed support is derived from the wall or ceiling, by aid of props arranged in the most conve- 
nient manner that presents itself. 

Fig. 549 is the common brace, which only differs from that in Fig. 54S in the left-hand screw ; a right- 
hand screw would be unwound in the act of drilling a hole when the brace is moved round in the usual 
direction, which agrees with the path of a left-hand screw. The cutting motion produces no change in 
the length of the instrument, and the screw being held at rest for a moment during the revolution, sets 
in the cut ; but towards the last, the feed is discontinued, as the elasticity of the brace and work suffice 
for the reduced pressure required when the drill is nearly through, and sometimes the screw is unwound 
Ftill more to reduce it. 


The lever-drill, Fig. 550, differs from the latter figure in many respects; it is much stronger, ana ap- 
plicable to larger holes ; the drill-socket is sufficiently long to be cut into the left-hand screw, and the 
piece serving as the screwed nut, is a loop terminating in the centre point. The increased length of the 
fever gives much greater purchase than in the crank-form brace, and in addition the lever-brace may 
be applied close against a surface where the crank-brace cannot be turned round ; in this case the lever 
is only moved a half circle at a time, and is then slid through for a new purchase, or sometimes a span- 
ner or wrench is applied directly upon the square drill-socket. 

The same end is more conveniently fulfilled by the ratchet-drill. Fig. 551. apparently derived from 
the last; it is made by cutting ratchet-teeth in the drill-shaft, or putting on the ratchet as a separate 
piece, and fixing a pall or detent to the handle ; the latter may then be moved backward to gather up 
the teeth, and forward to thrust round the tool, with less delay than the lever in Fig. 550, and with the 
same power, the two being of equal 
length. This tool is also peculiarly 
applicable to reaching into angles and 
places in winch neither the crank- 
form brace nor the lever-drill will 
apply. Fig. 552, the ratchet-lever, in 
part resembles the ratchet-drill, but 
the pressure-screw of the latter in- 
strument must be sought in some of 
the other contrivances referred to, as 
the ratchet-lever has simply a square 
aperture to fit on the tang of the 
drill d, which latter must be pressed 
forward by some independent means. 

Fig. 553, which is a simple but 
necessary addition to the braces and 
drill tools, is a socket having at the 
one end a square hole to receive the 
drills, and at the opposite, a square 
*ang to fit the brace ; by this con- 
trivance the length of the drill can be 
temporarily extended for reaching deeply-seated holes. The sockets are made of various lengths, and 
sometimes two or three are used together, to extend the length of the brace to suit the position of the 
prop ; but it must be remembered, that with the additional length the tortion becomes much increased, 




and the resistance to end-long pressure much diminished, therefore the sockets should have a bulk 
proportionate to their length. 

The French brace. Fig. 521, is also constructed in iron, with a pair of equal bevel-pinions, and a left- 
hand centre-screw like the tools, Figs. 549, 550, and 551 ; it is then called the corner-drill. Sometimes, 
also as in the succeeding Figs. 551 and 555, the bevel-wheels are made with a hollow square or axis, 
as in the ratchet-lever Fi". 552 ; the driver then hangs loosely on the square shank of the drill-tool, or 
cutter-bar, and when the pinion on the handle is only one-third or fourth of the size of the bevel-wheel 
w ith the square hole, it is an effective driver for various uses ; the long tail or lever serves to prevent 
the rotation of the driver, bv resting against some part of the work or of the work-bench. 

All the before-mentioned "tools are commonly found in a variety of shapes in the hands of the engineer, 
but it will be observed they are all driven by hand-power, and are carried to the work. I shall conclude 
this section with the description of a more recent drill-tool of the same kind. 

This instrument is represented of one-eighth size, in the side view, Fig. 556, in the front view, 557, 
and m the section, 558 ; it is about twice as powerful as Fig. 555, and has the advantage of feeding tho 

cut by a differential motion. The tangent-screw moves at the same time tiie two worm-wheels a and b; 
the former has fifteen teeth, and serves to revolve the drill ; the latter has 16 teeth, and by the 
difference between the two, or the odd tooth, advances the chill slowly and continually, which may be 
thus explained. 

The lower wheel a, of 15 teeth, is fixed on the drill-shaft, and this is tapped to receive the centre- 
screw c, of four tln-eads per inch. The upper wheel of 1 6 teeth is at the end of a socket d, (which is 
represented black in the section Fig. 558,) and is connected with the centre-screw c, by a collar and 
internal kev, which last fits a longitudinal groove cut up the side of the screw c ; now therefore the 
internal and external screws travel constantly round, and nearly at the same rate, the difference of one 
tooth in the wheels serving continually and slowly to project the screw c, for feeding the cut. To 
shorten or lengthen the instrument rapidly, the side-screw e is loosened ; this sets the collar and key 
free from the 1 6 wheel, and the centre-screw may for the time be moved independently by a spanner. 

The differential screw-drill, having a double thread in the large worm, shown detached at f, requires 
7 4 turns of the handle to move the drill once round, and the feed is one 64th of an inch for each turn of 
the drill ; that being the sum of 16 by 4. 

Drilling and Boring Machines. — The motion of the lathe-mandrel is particularly proper for giving 
action to the various single-cutting drills referred to ; they are then fixed in square or round hole drill- 
chucks which screw upon the lathe-mandrel. The motion of the lathe is more uniform than that of the 
handbook, and the popit-head, with its flat boring-flange and pressure-screw, form a most convenient 
arrangement, as the works are then carried to the drill exactly at right angles to the face. But in 
drilling very small holes in the lathe, there is some risk of unconsciously employing a greater pressure 
with the screw, than the slender drills will bear. Sometimes the cylinder is pressed forward by a 
horizontal lever fixed on a fulcrum ; at other times the cylinder is pressed forward by a spring, by a 
lack and pinion motion, or by a simple lever, and the best arrangement of this latter kind is that next 
to be described. 

In the manufacture of harps there is a vast quantity of small (hilling, and the pressure of the cylinder 
popit-head is given by means of a long, straight, double-ended lever, which moves horizontally, (at 
about one-third from the back extremity,) upon a fixed post or fulcrum erected upon the backboard of 
the lathe. The front of the lever is connected with the sliding cylinder by a link or connecting-rod, and 
the back of the lever is pulled towards the right extremity of the lathe, by a cord which passes over a 
pulley at the edge of the backboard, and then supports a weight of about twenty pounds. 

Both the weight and the connecting-rod may be attached at various distances from the fixed fulcrum 
between them. When they are fixed at equal distances from the axis of the lever, the weight, if 
tweuty pounds, presses forward the drill with twenty pounds, less a little friction ; if the weight be two 
inches from the fulcrum and the connecting-rod eight inches, the effect of the weight is reduced to five 
pounds ; if, on the other hand, the weight be at eight and the connecting-rod at two inches, the pressure 
is fourfold, or eighty pounds. 

The connecting-rod is full of holes, so that the lever may be adjusted exactly to reach the body of 
the workman, who, standing with his face to the mandrel, moves the lever with his back, and lias 
therefore both hands at liberty for managing the work. Sometimes a stop is fixed on the cylinder, fo» 
drilling hole? t n one fixed depth ; gages are attached to the flange for drilling numbers of similar pieces 



at any fixed distance from the udge : in fact, this very useful apparatus admits of many little additions 
to facilitate the use of drills and revolving cutters. 

Great numbers of circular objects, such as wheels and pulleys, are chucked to revolve truly upon the 
lathe-mandrel, whilst a stationary drill is thrust forward against them, by which means the concentricity 
between the hole and the edge is ensured. 

The chills employed for boring works chucked on the lathe, have mostly long shafts, some parts of 
which are rectangular or parallel so that they may be prevented from revolving by a hook-wrench, a 
spanner, or a hand-vice, applied as a radius, or by other means. The ends of the drill-shafts are pierced 
with small centre-holes, in order that they may be thrust forward by the screw of the popit-head, either 
by hand or by self-acting motion ; namely, a connection between either the mandrel or the prime mover 
of the lathe, and the screw of the popit-head, by cords and pulleys, by wheels and pinions, or other 

The drills, Figs. 52S and 530, are used for boring ordinary holes; but for those requiring greater 
accuracy, or a more exact repetition of the same diameter, the lathe-drills, Figs. 559 to 562, are 
commonly selected. Fig. 559, which is drawn in three views and to the same scale as the former 
examples, is called the half-round bit, or the cylinder-bit. The extremity is ground a little inclined to 
the right angle, both horizontally and vertically, to about the extent of three to five degrees. It is 
necessary to turn out a shallow recess exactly to the diameter of the end of the bit as a commencement , 
the circular part of the bit fills the hole, and is thereby retained central, whilst the left angle removes 
the shaving. This tool should never be sharpened on its diarr etrical face, or it would soon cease to 
deserve its appellation of half-round bit : some indeed give it about one-thirtieth more of the circum- 
ference. It is generally made very slightly smaller behind, to lessen the friction ; and the angle, not 
intended to cut, is a little blunted half-way round the curve, that it may not scratch the hole from the 
pressure of the cutting edge. It is lubricated with oil for the metals generally, but is used dry for hard 
woods and ivory, and sometimes for brass. 

The rose-bit, Fig. 560, is also very much used for light finishing cuts, in brass, iron, and steel ; the 
extremity is cylindrical or in the smallest degree less behind, and the end is cut into teeth like a 
countersink ; the rose-bit, when it has plenty of oil, and but very little to remove, will be found to act 
beautifully, but this tool is less fit for cast-iron than the bit next to be described. The rose-bit may be 
used without oil for the hard woods and ivory, in which it makes a veiy clean hole ; but as the end of 
the tool is chamfered, it does not leave a flat-bottomed recess the same as the half-round bit, and is 
therefore only used for thoroughfare holes. 

The drill, Fig. 561, is much employed, but especially for cast-iron work ; the end of the blade is made 
very nearly parallel ; the two front corners are ground sEghtly rounding, and are chamfered ; the 
chamfer is continued at a reduced angle along the two sides, to the extent of about two diameters in 
length; this portion is not strictly parallel, but is veiy slightly largest in the middle, or barrel-shaped: 
this drill is used dry for cast-iron. 

Fig. 561, in common with all drills that cut on the side, may, by improper direction, cut sidewise, 
making the hole above the intended diameter; but when the hole has been roughly bored with a 
common fluted drill, the end of the latter is used as a turning tool, to make an accurate chamfer ; the bit 
561 is then placed through the stay as shown in Fig. 562, and is lightly supported between the chamfer 
upon the work and the centre of the popit-head : the moment any pressure comes on the drill, its 
opposite edges stick into the inner sides of the loop, which thus restrains its position ; much the same as 
the point and edges of the turning tools for iron dig into the rest, and secure the position of those tools. 

It is requisite the drill and the loop should be exactly central Fig. 562 shows the co mm on form ot 
the stay when fitted to the lathe-rest, but it is sometimes made as a swing-gate, to turn aside, whilst 
the piece which has been drilled is removed, and the next piece to be operated upon is fixed in the 
lathe. Sometimes also the drill 561, has blocks of hard wood attached above and below it, to com- 
plete the circle ; this is usual for wrought-iron and steel, and oil is then employed. 

These three varieties are exclusively lathe-drills, and are intended for the exact repetition of a number 
of holes of the particular sizes of the bits, and which, on that account, should remove only a thin shaving 
to save the tools from wear. 

The cylinder bits, however, may be ustd for enlarging holes below half an inch, to the extent of about 
one-third their diameter at one cut ; and for holes from half an inch to one inch, alvut one-fourth their 



diameter or less ; and as the bits increase in size, the proportion of the cut to the diameter should 

The cylinder bit is not intr-cded to be used for drilling holes in the solid material, and as the piercing 
drills are apt to swerve in drilling small and very deep holes, the following rotation in the is 
sometimes resorted to. A diill, Fig. 531, say three-sixteenths diameter, is first sent in to the depth of 
an inch or upwards, and the h M is enlarged by a cylinder bit of cne-quarter inch diameter. The centre 
at the end of the hole is then restored to exact truth, by Fig. 532, a recentering drill, the plug of which 
exactly fits the hole made by the cylinder bit ; the extremity of the recentering drill then acts as a 
fixed turning-tool; and should the first drill have run out of its position, 532 corrects the centre at tho 
end of the hole. Another short portion is then drilled with 528. enlarged with the half-round bit, and 
the conical extremity is again corrected with the recentering drill ; the three tools are thus used in ro- 
tation until the hole is completed, and which may be then cleaned out with one continued cut, made 
with a half-round bit a little larger than that previously used. 

Some of the large half-round bits are so made, that the one stock will serve for several cutters of 
different diameters. In the bit used for boring out ordnance, the parallel shaft of the boring-bar 
slides accurately in a groove, exactly parallel with the bore of the gun ; the cutting blade is a small 
piece of steel affixed to the end of the half-round block, which is either entirely of iron, or partly of 
wood ; and the cut is advanced by a rack and pinion movement, actuated either by the descent of a 
constant weight, or by a self-acting motion derived from the prime mover. For making the spherical, 
parabolical, or other termination to the bore, cutters of corresponding forms are fixed to the bar* 

There are very many works which, from their weight or size, cannot be drilled in the lathe in its or- 
dinary position, as it is scarcely possible to support them steadily against the drill; but these works 
are readily pierced in the drilling-machine, which may be viewed as a lathe with a vertical mandrel, 
and with the flange of the popit-head enlarged into a table for the work, which then lies in the hori- 
zontal position simply by gravity, or is occasionally fixed on the table by screws and clamps. The 
structure of these important machines admits of almost endless diversity, and in nearly every manufac 
tory some peculiarity of construction may be observed. 

Figs. 564 and 565 exliibit Nasmyth's Portable Hand-drill, which is introduced as a simple and effi- 
cient example, that may serve to convey the general characters of the drilling-rnachines. The spindli 1 

is driven by a pair of bevel-pinions ; the one is attached to the axis of the vertical fly-wheel, the other 
to the drill-shaft, which is depressed by a screw moved by a small hand-wheel 

Sometimes, as in the lathe, the drilling-spindle revolves without endlong motion, and the table is 
raised by a treadle or by a hand-lever ; but more generally the chill-shaft is cylindrical and revolves in, 
and also slides through, fixed cylindrical bearings. The drill-spindle is then depressed in a variety of 
ways ; sometimes by a simple lever, at other times, by a treadle which either lowers the shaft only one 
single sweep, or by a ratchet that brings it down by several small successive steps, through a greater 
distance ; and mostly a counterpoise weight restores the parts to their first position when the hand or 
foot is removed. Friction-clutches, trains of differential wheels, and other modes, are also used in de- 
pressing the drill-spiudle, or in elevating the table by self-acting motion. Frequently also the platform 
admits of an adjustment independent of that of the spindle, for the sake of admitting larger pieces ; 
the horizontal position of the platform is then retained by a slide, to which a rack and pinion move- 
ment, or an elevating screw, is added. 

Drilling-machines of these kinds are generally used with the ordinary piercing-drills, and occasion- 
ally with pin-drills ; the latter instrument appears to be the type of another class of boring tools, 
namely, cutler-bars, which are used for works requiring holes of greater dimensions, or of superior accu- 
racy, than can be attained by the ordinary pointed drills. 

The small application of this principle, or of cutter-bars, is shown on the same scale as the former 
chills, in Fig. 566 ; the cutter c, is placed in a diametrical mortise in a cylindrical boring-bar, and is fixed 
by a wedge ; the cutter c extends equally on both sides, as the two projections or ears embrace the 
sides of the bar, which is slightly flattened near the mortises. 

Cutter-bars of the same kind, are occasionally employed with cutters of a variety of forms, for 

* The outside of the gun is usually turned, whilst the boring is going on, by the hand-tools. A plug of copper ij 
screwed into Hie brass guns to be perforated for the touch-hole, copper being less injured by repealed discharges than 
the alloy of y parts copper and 1 part tin, used for the general substance of the gun ; the curved bit smooths oIT the end of 
the plus. 


making grooves, recesses, mouldings, and even screws, upon parts of heavy works, and those which can 
not be conveniently fixed in the ordinary lathe. Fig. 567 represents one of these. 

i 1 ou '- V I S 

-s=s -&■ 

The larger application of this principle is shown in Fig. 568, in which a cast-iron cutter-block is keyed 
fast upon a cylindrical bar ; the block has four, six, or more grooves in its periphery. Sometimes the 
work is done with only one cutter, and should the bar vibrate, the remainder of the grooves are filled 
with pieces of hard wood, so as to complete the bearing at so many points of the circle ; occasionally 
cutters are placed in all the grooves, and carefully adjusted to act in succession — that is, the first stands 
a little nearer to the axis than the second, and so on throughout, in order that each may do its share of 
the work ; but the last of the series takes only a light finishing cut. that its keen edge may be the longer 
preserved. In all these cutters the one face is radial, the other differs only four or five degrees from the 
right angle, and the corners of the tools are slightly rounded. 

These cutter-bars, Hke the rest of the drilling and boring machinery, are employed in a great variety 
of waj-s, but which resolve themselves into three principal modes : 

First. The cutter-bar revolves without endlong motion, in fixed centres or bearings — in fact, as a spindle 
in the lathe ; the work is traversed, or made to pass the revolving cutter in a right line, for which end 
the work is often fixed to a traversing slide-rest. This mode requires the bar to measure, between the 
supports, twice the length of the work to be bored, and the cutter to be in the middle of the bar ; it is 
therefore unfit for long objects. 

Secondly. The cutter-bar revolves, and also slides with endlong motion, the work being at rest ; the 
bearings of the bar are then frequently attached in some temporary manner to the work to be bored, 
and are often of wood.* 

In another common arrangement, the boring-bar is mounted in headstocks, much the same as a trav- 
ersing mandrel, the work is fixed to the bearers carrying the headstocks, and the cutter-bar is advanced 
by a screw. The screw is then moved either by the hand of the workman, by a star-wheel, or a ratch- 
et-wheel, one tooth only in each revolution, or else by a system of differential wheels, in which the ex- 
ternal screw has a wheel, say of 50 teeth, the internal screw a wheel of 51 teeth, and a pah of equal 
wheels or pinions drives these two screws continually, so that the advance of the one-fiftieth of a turn 
of the screw, or their difference, is equally divided over each revolution of the cutter-bar, much the 
same as in the differential motion of the screw-drill, Fig. 556. 

This second method only requires the interval between the fixed bearings of the cutter-bar to be as 
much longer than the work, as the length of the cutter-block ; but the bar itself must have more than 
twice the length of the work, and requires to slide through the supports. 

Cutter-bars of this kind are likewise used in the lathe ; in the act of boring, the end of the bar then 
slides hke a piston into the mandrel. Such bars are commonly apphed to the vertical boring-machines 
of the larger kinds, which are usually fitted with a differential apparatus, for determining the progress 
of the cut ; the bar then slides through a collar fixed in the bed of the machine. 

In some of the large boring-machines either one or two horizontal slides are added, and by their aid, 
series of holes may be bored in any required arrangement. For instance, the several holes in the beams, 
or side-levers, and cranks of steam-engines are bored exactly perpendicular, in a hue, and at any precise 
distances, by shifting the work beneath the revolving spindle upon the guide or railway ; in pieces of 
other kinds, the work is moved Laterally during the revolution of the cutters, for the formation of elon- 
gated countersinks and grooves. 

Thirdly. In the Largest applications of this principle, the boring-bar revolves upon fixed bearings 
without traversing ; and it is only needful that the boring-bar should exceed the length of the work, by 
the thickness of the cutter-block, of which it has commonly several of different diameters. The cutter- 
block, now sometimes ten feet diameter, traverses as a slide down a huge boring bar, whose diameter 
is about thirty inches. There is a groove and key to couple them together, and the traverse of the 
cutter-block down the bar is caused by a side-screw, upon the end of which is a large wheel, that en- 
gages in a small pinion, fixed to the stationary centre or pedestal of the machine. With every revolu- 
tion of the cutter-bar, the great wheel is carried around the fixed pinion, and supposing these be as 10 
to 1, the great wheel is moved one-tenth of a turn, and therefore moves the screw one-tenth of a turn 
also, and slowly traverses the cutter-block. 

The contrivance may be viewed as a huge, self-acting, and revolving sliding-rest ; the cutter-bars are 
equally applicable to portions of circles, such as the D-valves of steam-engines, as well as to the 
enormous interior of the cylinder itself. 

All the preceding boring tools cut almost exclusively upon the end alone. They are passed entirely 
through the objects, and leave each part of their own particular diameter, and therefore cylindrical ; 
but I now proceed to describe other boring tools, that cut only on their sides, go but partly through the 

* Cylinders of 40 inches diameter for steam-engines have been thus bored by attaching a cast-iron cross to each end of 
the cylinder; the crosses are bored exactly to fit the boring-bar, one of them carries the driving-gear, and the bar is thrust 
endlong by means of a screw, moved by a ratchet or star wheel. 



work, and leave its section a counterpart of the instrument. These tools are generally conical, ami 
serve for the enlargement of holes to sizes intermediate between the gradations of the drills, and also 
for the formation of corneal holes, as for valves, stopcocks, and other works. The common pointed 
drill, or its multiplication in the rose countersink, is the type of the series ; but in general the broaches 
have sides which are much more nearly parallel. 

Broaches for making taper holes. — The tools for making taper holes, are much less varied than the 
drills and boring tools for cylindrical holes. Th-js the carpenter employs only the rimer, which is a 
fluted tool like the generality of his bits; it is sharpened from within, as shown in Fig. 569, so as V 
act like a paring tooL Flutes and clarionets are first perforated with the nose-bit, and then broached 
with taper holes, fcy means of tools of this kind, which are very carefully graduated as to their dimen 
sions. Fig. 570 represents a German rimer, used by wheelwrights for inlaying the boxes of axletrees ; 
the loose blade is separated from the shell of the instrument, by introducing shps of leather or wood 
between the two ; the detached cutter fits on a pin at the front, and is fixed by a ring or collar agaiust 
Jie shaft. 

A curious rimer for the use of wine-coopers, by which the holes were made more truly circular, and 
the shavings were prevented from dropping into the cask. The stock of the instrument consists of a 
hollow brass cone, seen in section in Fig. 571; down one side there was a slit for containing a narrow 
blade or cutter, fixed by three or four screws placed diametrically. The tube was thus converted into 
a conical plane ; the shavings entered within the tube, and were removed by taking out a cork from 
the small end of the cone. 

The broaches for metal are made solid, and of various sections; as half-round, like Fig. 572 ; the 
edges are then rectangular. But more commonly the broaches are polygonal, as in Fig. 573, except that 
they have 3, 4, 5, 6, and 8 sides, and their edges measure respectively GO, 90, 108, 120, and 135 degrees. 
The four, five, and six-sided broaches are the most general, and the watchmakers employ a round 
broach in which no angle exists, and the tool is therefore only a burnisher, which compresses the metal 
and rounds the hole. 

Ordinary broaches are very acute, and Fig. 574 may be considered to represent the general angle at 
wlueh their sides meet — namely, less than one or two degrees ; the end is usually chamfered off with 
as many facets as there are sides, to make a penetrating point, and the opposite extremity ends in a 
square tang, or shank, by which the instrument is worked. 

Square broaches, after having been filed up, are sometimes twisted whilst red-hot. Fig. 577 shows 
one of these ; the rectangular section is but little disturbed, although the faces become slightly concave. 
The advantage of the tool appears to exist in its screw form : when it is turned in the direction of the 
spiral, it cuts with avidity and requires but little pressure, as it is almost disposed to dig too forcibly 
into the metal : when turned the reverse way, as in unscrewing, it requires as much or more pressure 
than similar broaches not twisted. This instrument, if bent in the direction of its length, either in the 
act of twisting or hardening, does not admit of correction by grinding, like those broaches having plane 
faces. It is not much used, and is almost restricted to wrought-iron and steel. 

Large countersinks that do not terminate in a point, are sometimes made as solid cones ; a groove is 
then formed up one side, and deepest towards the base of the cone, for the insertion of a cutter, (see 
Fig. 574.) As the blade is narrowed by sharpening, it is set a little forward in the direction of its 
length, to cause its edge to continue slightly in advance of the general surface, like the iron of a plane 
for cutting metal. 

Fig. 579 represents Mr. Richard Roberts' broach, in which four detacher blades are introduced, for 
the sake of retaining the cone or angle of the broach with greater facilitv The bar .->r stock has four 

shallow longitudinal grooves, which are nearly radial on the cutting face, and slightly undercut on the 
other The grooves are also rather deeper behind, and the blades are a little wedge-form both in sec- 
tion and in leugth, to constitute the cone, and the cutting edges. In restoring the edges of the blades, 

hey are removed from the stock, and their angles are then more easily tested : when replaced, they are 

et nearer to the point, to compensate for their loss of thickness. 

Broaches are also used for perfecting cylindrical holes, as well as for making those which are taper 
The broaches are then made almost parallel, or a very little the highest in the middle ; they are fileo, 
with two or three planes at angles of 90 degrees, as in Fig. 575 or 576. The circular part not being 
able to cut, serves as a more certain base for foundation, than when the tool is a complete polygon ; and 
the stems are commonly made small enough to pass entirely through the holes, which then agree very 
exactly as to size. Such tools are therefore rather entitled to the name of finishing drills, than bro^cbei 

BEAKES. 183 

The size of the parallel broaches is often slightly increased, by placing a piece or two of paper at 
the convex part ; leather and thin metal are also used for the same purpose. Gun-barrels are broached 
with square broaches, the cutting parts of which are about eight to ten inches long ; they are packed 
on the four sides with slips or spills of wood, to complete the circle, as in Fig. 577, in which the tool ia 
supposed to be at work. The size of the bit is progressively enlarged by introducing slips of thm 
paper, piece by piece between two of the spills of wood and the broach ; the paper throws the one 
angle more towards the centre of the hole, and causes a corresponding advance in the opposite or the 
cutting angle. Sometimes, however, only one spill of wood is employed. 

A broach used by the philosophical instrument makers in finishing the barrels of air-pumps, consisted 
of a thin plate of steel inserted diametrically between two blocks of wood, the whole constituting a 
cylinder with a scraping edge slightly in advance of the wood ; slips of paper were also added. 

According to the size of the broaches, they are fixed in handles like brad-awls ; they are used in the 
brace, or the tap-wrench — namely, a double-ended lever with square central holes. Sometimes also 
broaches are used in the lathe just like drills, and for large works, broaching machines are employed; 
these are little more than driving-gear terminating in a simple kind of universal joint, to lead the power 
of the steam-engine to the tool, which is generally left under* the guidance of its own edges, according 
to the common principle of the instrument. 

In drills and broaches, the penetrating angles are commonly more obtuse than in turning tools ; thus 
in drills of limited dimensions, the hook-form of the turning tool for iron is inapplicable, and in the 
larger examples, the permanence of the tool is of more consequence than the increased friction. But 
on account of the additional friction excited by the nearly rectangular edges, it is commonly necessary 
to employ a smaller velocity in boring than in turning corresponding diameters, in order to avoid soften- 
ing the tool by the heat generated ; and in the ductile fibrous metals, as wrought-iron, steel, copper, 
and others, lubrication with oil, water, ±c, becomes more necessary than in turning. 

The drills and broaches form together a complete series. First the cylinder-bit, the pin-drills, and 
others with blunt sides, produce cylindrical holes by means of cutters at right angles to the axis ; then 
the cutter becomes inclined at about 45 degrees, as in the common piercing-drill and cone countersink; 
the angle becomes much less in the common taper broaches; and finally disappears in the parallel 
broaches, by which we again produce the cylindrical hole, but with cutters parallel with the axis of 
the hole. 

Still considering the drills and broaches as one group, the drills have comparatively thin edges, always 
less than 90 degrees, yet they require to be urged forward by a screw or otherwise, the resistance being 
sustained in the hue of their axes. The broaches have much more obtuse edges, never less than 90, and 
sometimes extending to 135 degrees ; and yet the greater force required to cause the penetration of their 
obtuse edges into the material, is supplied without any screw, because the pressure in all these varied tools 
is at right angles to the cutting edge. 

Thus supposing the sides of the broach extended until they meet in a point, as in Fig. 57S, we shall 
find the length will very many times exceed the diameter, and by that number will the force employed 
to thrust forward the tool be multiplied, the same as in the wedge, whether employed in splitting timber 
or otherwise ; and the broach being confined in a hole, it cannot make its escape, but acts with great 
lateral pressure, directed radially from each cutting edge ; and the broach under proper management 
leaves the holes very smooth and of true figure. 
BOX-WOOD. See Woods, varieties nf. 
BRACE. See Bokixg Tools. 


BRAKE. The drag applied generally to the wheels of carriages to check their velocity in passing 
down hills, by means of friction. The brake attached to railway carriages consists of a piece of wood, 
which is pressed upon the rim of the wheels of the carriages by a hand-lever, worked by the brakeman. 
The brake of the tender alone affords a sufficient resistance to stop a train under ordinary circumstan- 
ces. The term is also used in reference to the contrivance for arresting the motion of machinery. 

On English railways brakes are applied to the wdieels of a part only of the carriages attached to a 
train ; these are termed guard vans. The number of these brake carriages depending upon the incli- 
nations of the line and the speeds employed. The engine also is generally reversed to assist the brakes. 
It must be recollected, however, that by stopping a train too rapidly, great injury results both to the per- 
manent way and the rolling stock. 

The following considerations should determine the amount of brake power required. 
The forces which act on the train after the steam has been shut off, are the axle friction and rolling 
friction of the train, and the pressure of the wind ; the friction tends gradually to bring the train to 
rest, the pressure of the wind to accelerate or retard it, as the ease may be, and this will therefore be 
omitted from the conclusions to be drawn. 

To stop a train rapidly, brakes are applied to some of the wheels, and the engine is reversed. The 
application of brakes prevents the wheels from revolving, and introduces the friction due to the weights 
on the wheels to which brakes are applied. The act of reversing the engine does not immediately stop 
the forward motion of the driving wheel, but forces it to revolve at a somew.bat slower rate than that 
due to the speed of the train, and thus causes a friction of surfaces to take place between the wheel 
and rail. 

The axle and rolling friction may be assumed to be some proportion of the total weight of the train ; 
the friction of the wheels to which brakes are applied may be taken as some proportion of the insistent 
weights : by experiment on English railways, it appears that the axle and rolling friction may he taken 
at -jl-j part of the weight of the train, and the friction due to the brakes at about \ of the weight on 

184 BRAKES. 

Hence, if I represent the gross load of the train, 

w " the weight on the wheels to which brakes are applied, 
R " the retardation in feet per second, 
q " the force of gravity, 
and, if the train be on an incline, 

represent the slope of such incline, 


L334 8 p J V 

the latter term being used with the negative sign when the train is descending, and the positive sig» 
when ascending the gradient. 

If S = space traversed by the train in coming to rest, 

v = velocity in feet per second at the moment the steam is shut off and the brakes applied, 

v 2 

In estimating practically the space which would be required for a train V- top in, eight or ten seconds 
should be allowed for time lost in applying the brakes. 

Since more than half the total number of fatal accidents which occur upon railroads arise from colli- 
sion, it is important that the attention of railroad companies should he specially directed to precautions 
against this source of danger. The possibility of preventing collision will depend upon the proportion 
which the number of brakes and brakemen npon the train bears to its weight and speed. It is found 
by experience that the distance within which a train of given weight can be brought to rest by a given 
number of brakes, will be in proportion to the square of its speed, that is to say, with a double speed 
it will require four times the number of brakes; with a treble speed nine times the number of brakes, 
and so on. 

The means of stopping a train are, the brake on the tender, the brakes on the cars, and in fine, re- 
versing the action of the engine. This is a dangerous process. In this way the whole force of the steam 
is suddenly made to resist the progressive motion of the engine; the cars are consequently urged against 
the engine, and against each other, and the obvious tendency is to throw the cars from the rails by 
doubling vp the train. Before reversing the engine, or even applying the brake to the tender, it is there- 
fore advisable to warn the brakemen to apply the brakes to the cars composing the train ; this being 
done, and the brake being then applied to the tender, there is less danger in reversing the steam on the 
engine, the whole train remaining elongated by the friction of the brakes applied to the rear cars. 

The common form of car brake at present in use, is operated by a brakeman standing on the plat- 
form at either end of the car. A vertical rod turning in a step at the bottom is made to wind up by 
means of a hand wheel, a few links of chain connecting by an iron rod with a lever attached to the bot- 
tom of the car. This lever acts directly on a heavy wooden bar suspended from the car trucks by hooks 
and chains at either end. The ends of these bars support the friction blocks, which are of wood lined 
with metal, and are made to bear directly upon the periphery of the wheel. By means of a small 
ratchet wheel and detent on the platform, the vertical rod is held stationary when the brakes are put on, 
and is released when the motion of the train is stopped ; the action of this form of brake is direct, sim- 
ple and efficient. 

Various forms of self-acting brakes have been devised, and much ingenuity has been displayed in the 
endeavour to obtain this object, and although none of them are as yet in general use, the importance of 
security from accident in railway travel, demands a careful investigation of the best methods of pre- 
venting collisions by this means. 

In " Lougkridge's Self-acting Car Brake," the cars are stopped by the friction of the ordinary brakes, 
but the power actuating them is derived directly from a drum shaft on the locomotive. This shaft, or 
rather pulley keyed thereon, is pressed into contact with the flange of the driving wheels, and is thus 
compelled to revolve and wind up a stout chain running the length of the train beneath the cars. This 
chain applies the brakes of all the cars. To prevent pulling too severely and fracturing some portion 
of the mechanism, provision is made for limiting the extent of its action by causing it to release its hold 
of the driving wheel so soon as a certain portion of the chain is taken up. The point at which this un- 
shipping movement comes into play is previously arranged by the engineer, so that however excited in 
view of danger, or careless and bungling, he cannot endanger the integrity of any important part. 

To cause one continuous chain to operate all the brakes, an ingenious arrangement is adopted. A 
stout lever, some three or four feet long, is hung under each car, and provided with sheaves or pulleys 
at each end, around which the chain makes a curve like the letter S, and continues on to the next. 
"When the. chain is pulled by the winding of the shaft, this lever is moved by the tension, and forces the 
brakes into contact with the wheels. 

The United States Railroad Car Brake of Wm. G. Creamer, is an improved method of operating 
brakes, by bell or signal cords, as represented in tig. 580. 

The principal features of this invention and its operation, are as follows: — To the ordinary hand 
wheel and brake-shaft, (for winding up the brakes,) is attached a drum A or loose pulley containing a 
strong spiral spring. This spring is wound up by a reverse motion of the brake-shaft, to which is at- 
tached an arm and pawl G, taking into a circle of ratchet teeth on the top of the drum A. "When the 
spring is wound ready for use, it is held in check by a lever B, from the extremity of which passes k 
branch line to the top of the car at D, and connecting about three feet forward to the bell-cord. The 
branch line is attached to the lever B by a ring in such a way that when the lever is drawn up verti- 
tally the ring disconnects. This is rendered necessary to insure the working of the brakes by the bell- 
cord whether the train is extended on an up grade, or contracted on a down grade. The attachment 



of the branch line of each car, some three feet forward, enables the engineer to apply the brakes of all 
the cars simultaneously, by pulling the bell-cord, and at the same time it does not interfere with the 
bell-cord as a means of enabling the conductor to signalise the engineer. When the conductor pulls 
the bell-cord it rin"S the bell, and simply makes slack on the several branch lines connected with the 
brake, but does not operate the brake. The conductor, brakeman, or even passengers however can, if 
nn emergency arises in any part of the train, instantly close all the brakes, by pulling the bell-cord, or 
any accidental separation of the train produces the same effect, namely, bringing tli3 retarding force 
on all the cars into instant action. 

A train has been repeatedly stopped with this apparatus within 350 feet at 30 miles per hour ; the 
brakes being shod with east iron ; with wooden shoes, a train may be stopped within 250 feet. 

The advantages claimed for this 
invention are as follows : 

First. — It enables the Engine- 
man iu any sudden emergency or 
premonition of danger, instantly 
to apply the brakes of every car 
of the train, (without signals or 
brakemen,) with their utmost pow- 
er, and hold each car by itself, 
independent of each other, even if 
the engine or a part of the cars 
are thrown from the track. 

Second. — It also enables the 
conductor, brakeman, or even pas- 
sengers of the train, whether mov- 
ing forward or backward, in front 
or rear, iu any emergency, to ap- 
ply every brake of the entire train 
in an instant, without reference to 
its length. 

Third. — It involves no altera- 
tion in the construction or method 
of working the present brakes, 
puts uo additional machinery or 
apparatus under the cars, exposed 
to dust and friction, and where it 
cannot be seen when the train is 
in motion, but places the entire 
mechanism on the platform, where 
it is constantly under the eye of 
the brakeman and attendants of 
the train. 

Fourth. — Each car having an 
independent arrangement of its 
own, a train can be made up with 
a part of the cars fitted with this 
apparatus and a part without. 
Those fitted with the apparatus can 
be connected with the bell-cord, 
and when required, the brakes can 
he worked as previously described. 
This will be a great advantage 
where passenger cars are behind 
freight or cattle trains. 

Fifth. — No additional machinery or mechanism is required on the engine. Xo additional responsi- 
bility is put upon the engineer. In case of danger, instead of giving the usual siguals, he would give 
the bell-cord a jerk, (which would apply every brake instantly,) and reverse his engine. He could 
then jump off if he chose. 

Sixth. — This improvement does not interfere with the use of the signal-cord for transmitting signals 
to the engineer, nor does it interfere with the use of the brakes by hand, even when set, and ready for 
use by the bell-cord. While the brake is being applied by hand, the engineer can release the latch and 
finish the work in an instant. The connection of the brake operator with the hand- wheel can he 
maintained constantly without interrupting the operation of either plan. 

Seventh. — This apparatus being connected to, and identified with the common brake-shaft under the 
■ hand-wheel, its position is such, that it is constantly seen by the brakeman or attendants of the train ; 
and if out of order, the fact is immediately known, and the remedy applied. This would not be the 
case if it were placed on the top, or under the car, or anywhere out of constant sight. 

Eighth. — Two brakemen are all that is really necessary in a train of any length, or (not exceeding 
eight cars) so far as the ordinary stoppages are concerned, while at the same time, the means are at 
hand for the instant and powerful application of every brake from any part of the train if required. 
In any such case it would be necessary for the brakeman to go to each car and release the brakes. 
Such emergencies would not of course be of daily occurrence, and the time required would not exceed 



a minute, "winch is a matter of no consequence whatever. If brakemen are placed for every two cars, 
as ordinarily, the whole brakes could be released in a moment as now on signal. 

The damage from breaking of a chain, or rail, or wheel, or axle, will be greatly mitigated on trains 
where this invention is used. In the first place, in sudden danger the engineer does not give the signals, 
or if given at all, they are given hurriedly, and perhaps not heard or understood, or if heard at unex- 
pected places, the brakeman, if on the platform, cannot avoid the temptation to look out and see what 
is the matter ; if there is an impending crash in view, he cannot resist the inclination to jump off, or 
at least to get inside the car ; no man under the circumstances can deliberately exert his whole strength 
on the platform ; the consequence is, that little or nothing can be done towards averting an accident by 
the present brakes as applied by hand. Trains never can, or never will, be run without brakemen 
or attendants ; at least two men are wanted besides the conductor, for baggage and brakes on trains of 
four or five cars. They are called brakemen, but the application of the brakes, for all ordinary purposes, 
is a very small portion of their duties. They have to clean the cars, trim the lamps, examine the 
boxes, make the fires, wood up at stations, take back signals, &c, tic. Just as many men would be 
wanted, supposing they would not be wanted as brakemen. 

This apparatus may be described as a mechanical connection of all the brakes of the train in one control- 
ling power, and that furnishes the means of direct and instant application, perfectly accessible from the engine 
or any part of the train. 

Carriage Brakes.— Carriages have recently been constructed in a peculiar manner for a turnpike road 
over the summit of Mount AVashington. They are made to stand at different angles, so that the floors 
nre always nearly level ; and they are provided with brakes operated at will by the hand of the driver, 
or by the backward strain of the horses. The brakes are operated by a strap passing around a pulley 
or ring in the forward extremity of the pole or tongue. At every declivity, the carriage in crowding 
forward upon the horses, tightens the strap, and brings the brakes in contact with the wheels. When it 
becomes necessary to back the carriage, a bolt is dropped by the driver which renders the brakes in- 

Fig. 581, represents a convenient form of " Prony's Friction Brake," a dynamometrical instrument 
used to measure the power applied to, and mechanical effect produced by a revolving shaft, or other re- 
volving part of a machine. It consists of a lever, to one end of which a balance scale or weights may 
be attached, and of two wooden segments fitted to a friction pulley, keyed upon the revolving shaft, and 
which can be tightened to it by means of screw bolts. To measure by means of this arrangement, 
the power of the axis for a given number of revolutions, the extremity of the lever is weighted, and the 
screw bolts drawn up until the shaft makes the given number of revolutions, and the lever maintains a 
horizontal position. In these circumstances the whole mechanical effect expended is consumed in over- 
coming the friction between the shaft and the wooden segments, and this mechanical effect is equal to 
the work or useful effect of the revolving shaft ; as the lever has free movement, it is only the fric- 
tion acting in the direction of the revolution that counterbalances the weight at the end of the lever, 
and the friction may be deduced from the weight. 

To calculate the power, multiply together the length of the lever in feet, the'weight in lbs., the num- 
ber of revolutions of the shaft per minute, and the number 6.2832 (2 jr) : the result will be the lbs. 
raised 1 foot per minute, and this divided by 33,000, is the horse power. In order to counteract the 
tendency of the end of the lever to oscillate, a dash pot is used, having a piston working in a cylinder 
filled with water. See Dynamometer. 

In " Ewer's Friction Brake" a cast iron friction ring is fastened by three pairs of screws on any sized 
shaft that will pass through the ring. For the wooden segments an iron band is substituted, embracing 
half the circumference of the iron ring. The band ends in two bolts passing up through a wooden 
beam and may be tightened at will by means of screw nuts. To prevent the firing of the wood, or 
excessive heating of the iron, water is constantly supplied through a small hole in the beam. 

Example. To determine the mechanical effect produced by a water wheel, a friction brake was 
placed in the shaft, and when the water let on had been perfectly regulated for six revolutions per min- 
ute, the weight G, including the reduced weight of the instrument, was 530 lbs. ; the leverage of this 
weight was a = 10.5 feet. From these quantities the effect given off by the water wheel is deduced. 
L = tt. 6. 10.5 . 53 = 3^97 f eet . lbs. r= 6.3 horse power. 

BRAN" SEPARATOR. This is the invention of E. R. Benton, of Milwaukie, Wisconsin, and it ha3 
been deemed one of no minor importance. The following description of its construction and operation, 
in connection with the accompanying engravings, will enable our readers fully to understand it. 

Fig. 581 is a sectional view, and Fig. 583 a sectional plan, with the top parts removed in order moro 
slainly to show the parts represented in Fig. 582 A, is the shaft. B, the cylinder, C, the inner re- 



volving shell ; and D, the outer or stationary shell. The cylinder is made by framing staves of tha 
form, and in the position represented at 1, 2, 3, ifcc., Kg. 583, into corresponding cast heads. The staves 
thus forming the longitudinal and working surface, and which may be covered with any kind of material 
that will make it rough and durable. Air is let into the cylinder, the best at the lower end, through 
equidistant holes around the centre, and the quantity gaged by a circular revolving slide, and spaces 
between the staves emit it to carry the flour and other stuffs through the several qualities of wire cloth 
with which the inner surface of the revolving shell is covered. The cylinder is driven by a belt and 

pulleys, as is represented at the bottom of Fig. 5S2 ; and the bridge and oilpot for the point and step, 
and the fixture for supporting the upper journal-box of the shaft, are cast in a piece with their respec- 
tive heads of the outer shell thus rendering this part of the machine perfect. The inner surface of the 
revolving shell is covered with the above-named wire-cloth. Thus, the space between the top and the 
bevelled dividing ring E, Fig. 582, is covered with a quality that will let through little else but pure 
flour, which falls, and by the dividing ring is conducted into an endless trough I, attached to the 
inner and sheet-iron or zinc-lined surface of the stationary shell and by the sweepers F, attached 
to the revolving shell is brought around and discharged at the spout ft The space between the divi- 
ding rings E and H is covered with a quality that will discharge an inferior quality to the above, which 
falls, as above into the endless trough J, and by the sweepers K, is brought around and discharged at 
the spout L. The space between the dividing rings H and M is covered with a quality that will take 
out the fine particles of the bran, called dusting, which falls, as above, into the endless trough N, and by 
the sweepers 0, is discharged at the spout P. The space between the dividing ring M and the bottom, 
is covered with a quality that will separate the shorts from the bran, the shorts falling to the bottom, 
or into the endless trough R, and by the sweepers S is discharged at the spout T, the bran passing down 
inside of the revolving shell and by the arms IT, of its cast head, is swept around to, and discharged 

188 BREAD. 

at the spout V. The revolving shell is driven by a combination of gear-wheels, thus : The pinioc 
above, on the principal shaft A, Fig. 5S2, drives the wheel X, on the small or centre shaft Y, and the 
pinion Z, on the last-named shaft, drives the projecting cogged-wheel run a, cast in a piece with the top 
head, wliich will turn it the same way with the cylinder ; and to turn it the contrary way, the project- 
ing r im a must be so large as to circumscribe and be driven by the pinion Z, working into cogs upon its 
inner periphery, as seen by the figures W, of pitch circles, the figures denoting the corresponding pitch 
circles of the wheels and pinions in Fig. 5S2. b, is a circular inclined plane, so calculated as to 
lift a mallet or hammer to strike upon the end of the revolving shell to keep the cloth from clog- 
ging, the blow to be struck upon a block resting upon its upper rim, and projecting up through a cor- 
responding hole in the stationary head, as at C. d, is a set of cams on the shaft Y, which shake a 
wire sieve e, that receives the uncleaned and unseparated bran, shorts, and dustings from the bolts, as 
through the spout/, the sieve carrying off all coarse extraneous stuff that might injure the machine, 
the bran falling through the sieve and entering the machine passing between the arms of the upper 
head of the revolving shell on to the head of the cylinder. 

BRASS. See Metals and Allots. 

BRASSES. A term applied by mechanics to boxes or bushings of brass. 

BRAZILETTO. See Woods, varieties of. 

BRAZIL-WOOD. See Woods, varieties of. 

BFiAZING, the soldering together of edges of iron, copper, brass, &c, with an alio}' of brass and 
line, called spelter solder. 

BREAD. The only substance adapted to the making of good fermented bread is the flour of wheat. 
The essential constituents of wheat flour are starch, also called farina or fecula, gluten, and a little 
albumen. According to Yogel, 100 parts of wheat flour contain, of starch OS parts, gluten 24, gummy 
sugar 5, and albumen 1-5 ; but these proportions vary with the goodness of the wheat. 

The starch of wheat flour is very nutritive. Gluten is a mixture of vegetable fibrine, and a small 
quantity of a peculiar matter containing nitrogen, called gliadine, to which its adhesive properties are 
due. The small proportion of sugar in wheat flour enables it to ferment on being mixed with water, 
without the addition of yeast. Thus the dough of wheat flour, by spontaneous fermentation, becomes 
converted into leaven. 

During the rising of the dough, carbonic acid is formed at every part, and is prevented from escaping 
by the gluten, which forms a kind of adhesive web. The formation of this gas causes the dough to 
swell in every direction, and the particles of starch to separate, in which condition the process is arrested 
by the heat of the oven, so that when the bread is cut open, it is piled full of cavities, each of which in 
the dough contained a globule of carbonic acid. 

In the preparation of wheat for the manufacture of bread, the ground grain is usually separated into 
three parts, the flour, the pollard, and the bran; the flour forms, on an average, about three-fourths of 
the wheat ground. The white flour is pleasing both to the eye and taste, and there is a strong preju- 
dice in favor of white bread ; hence various methods of bleaching are resorted to, but it is doubtful if 
the whitest bread, even supposing it to be pure, is conducive to health and economy. By rejecting the 
bran, as we do when using only the finest flour for bread, we actually lose a large amount of nourish- 
ment of the most important kind. According to Liebig, the separation of bran from the flour is rather 
injurious than useful to nutrition. By using unbolted flour for bread the product is increased at least one 
fifth. From the several varieties of flour obtained by bolting, three kinds or classes of bread are man- 
ufactured. 1. Wheaten bread, or firsts, which is made of the finest flour ; 2. household bread, OTseeonds, 
which is somewhat coarser; 3. brown bread, thirds, which is made of flour of various degrees of coarse- 
ness. F^or making firsts, the flour is entirely separated from the bran or husks ; in the other descrip- 
tions the bran is not entirely removed, but the coarse broad bran is separated from the coarsest 

The baker generally takes a portion only of the water which he intends to employ in makiug the 
required quantity of dough, at a temperature of from 70° to 100°, and containing a portion of salt 
necessary to give the bread its proper flavor. Yeast is next mixed with the water, and then a portion 
of flour is added, always less than the quantity intended for the finished dough. The mixture is cov- 
ered up and left in a warm situation. In about an hour this mixture, termed the sponge, thus set apart, 
begins to ferment. It swells out and heaves up, evidently in consequence of the generation of some 
internal elastic fluid, which, in this instance, is carbonic acid gas. When no longer capable of retaining 
the pent-up air, it bursts and subsides. Alter the second or third rising and dropping of the sponge, 
the baker interferes, otherwise the bread formed from this dough would be sour. At this period lie 
therefore adds to the sponge the remaining portions of flour and water and salt, necessary to form the 
dough into the required consistence and size, and next incorporates all these materials with the sponge, 
by long and laborious kneading. The dough is left to itself for a few hours, during which time it con- 
tinues in an active state of fermentation throughout its whole extent. After a second kneading, to 
distribute the gas within it as equally as possible throughout the whole mass, the dough is weighed out 
into portions requisite to form the kinds of bread desired. These loaves are once more set aside for an 
hour or two in a warm place, and the continued fermentation soon expands each mass to about double 
its former volume. They are now considered fit for the fire, and are finally baked into loaves, which 
when they quit the oven, are nearly twice as large as when they entered it. The gas contained in the 
bread is expanded by the heat throughout every part of the loaf, and swells out its whole volume, 
giving it the piled vesicular structure. Thus a well-made and well-baked loaf is composed of an in- 
finite number of cellules, each of which is ailed with carbonic acid gas, and lined with, or composed of, 
a glutinous membrane ; aud it is this that communicates the light, elastic, porous texture to bread. 

Various arrangements are in use for making bread by machinery. The usually laborious occupation 
rf kneading and mixing the dough is now perfectly well performed by mechanical means, and automatic 

BREAD 189 

ovens receive the dough and return it baked to the basket. Thus large quantities of perfect bread are 
made expeditiously and at a low price. 

The following is a description of Berdan's Automatic Oven, in Brooklyn, N. Y. : 

" The oven is of brick, eighteen feet long, niue feet broad, and thirty-two feet high, having a lower 
and upper story. Underneath the oven is a furnace, from which the heat is conducted to, and through 
the oven, by means of fire-brick tubes ; and the furnace is so constructed and arranged that, by means 
of a self-acting damper attached to a piece of metal, which opens and shuts as the metal contracts and 
expands, the heat in the oven can be regulated and kept constantly at the same temperature. The 
mercury stands at about 202 degrees. There are four doors or entrances to this oven ; two in the 
lower, and two in the upper story. Within the oven is an endless chain, to which arms are attached, 
and upon which thirty-two forms are laid, about two feet apart. This chain can be moved either by 
band or by steam power (the latter being used for convenience and economy in the present case, there 
being a steam engine on the premises), and revolves perpendicularly through the oven at just that rate 
of speed as is required to bake the bread with a single revolution ; and by means of a conical cylinder, 
the time of the revolution can be regulated to the fraction of a minute. These thirty-two platforms 
support thirty-two large bread-pans. Outside, and by the doors of the oven, are two waiting or tender- 
cars, and all these cars and oven-doors are moved by the same power that moves the endless chain. 

" When it is put in motion, one of the oven-doors rises of its own accord, an empty pan trundles out 
of the oven, and is placed upon the tender-car, by which it is carried to a door on the other side of the 
oven. A pan containing sixty loaves of dough is placed on this car. The door opposite to which the 
car is, opens, and the loaded pan at once moves into the even : the door instantly closes after it, and 
the pan commences its revolution upon the endless chain. Immediately after the close of this door, the 
other door opens, and another empty pan moves out, is filled at once with its freight of dough, aud then 
takes its station, like its predecessor at the first door, and follows after in the same manner until the 
thirty-two cars are filled — the pans always entering at one door and issuing at the other. From the 
time that all the pans are loaded, a pan of baked bread comes out and dumps itself at one door of the 
oven as fast as the dough is put in at the other door." 

At present the ships of the English navy are supplied with ship-bread, or biscuit, made by machinery, 
before the introduction of which they were made by hand. In 1833 an apparatus was constructed for 
this purpose by Mr. Grant, of Gosport. The first process is the preparation of the dough for bakino-. 
The meal is conveyed into a cylinder il feet long, 3 feet 2 inches in diameter, and water is let in from 
a cistern at the back of the cylinder, regulated by a gauge to the exact quantity required for mixing 
the meal. Through the centre of the cylinder is fitted a shaft armed with knives, and working hori- 
zontally. The shaft being set in motion, the knives revolve through the meal and water. During the 
first half minute the meal and water do not appear to unite ; but after this the dough begins to assume 
a consistency, and in two minutes 5 cwt. of well-mixed dough is produced. The cylinder is formed so 
that its lower half is easily separated by means of a wheel and pinion from the upper sides, thereby 
forming a trough containing the dough, from which it is removed, and placed under the breaking- 
rollers to be kneaded. These rollers, two in number, weigh 1500 pounds each, and are propelled from 
off a two-throw crank-shaft by means of connecting rods and pendulums ; they pass backwards and 
forwards over the dough during five minutes, when the 5 cwt. of dough is brought into a solid, perfect, 
and equal consistency. From the breaking-rollers the dough is cut into pieces 18 inches square, and 
placed on boards 6 feet long by 3 feet wide, which are conveyed, by means of a line of friction-rollers 
connected by an endless chain, under a second set of rollers, to be rolled to the required thickness of 
the biscuit. The square of dough being thus pressed out, so as to cover the surface of the board on 
which it is transferred under the cutting and stamping-plate, is at the same moment cut and stamped, 
or docked, into 42 hexagonal biscuits, which, being now complete, are at once conveyed to the oven on 
carriages constructed for the purpose. The hexagonal shape is preferred in order that there may be no 
waste, the sides of each biscuit fitting accurately into those adjoining. The hexagonal cutters do not 
completely separate the biscuits, so that a whole sheet of them can be put into the oven at once, and, 
after being withdrawn, they are broken asunder by hand. The grain for the biscuits is prepared at 
the Government mills ; it is a mixture of fine flour and middlings. The ovens are of wrought iron, 
with an area of 160 square feet. About 112 lbs. weight of biscuits is put into the oven at ore time; 
this is called a suit, and is reduced to about 100 lbs. b} r the baking. 

The bake-house at Gosport was provided with one mixing machine, two breaking-rollers, four sheet- 
rollers, and four stampers; and it was calculated that this machinery would require eight men and 
eight boys to supply the nine ovens; that the produce per hour would be 10,000 biscuits, or one ton of 
bread, at a cost for labor and other incidental expences of S^d. per cwt. It was found, however, iu 
practice that the machinery could easily supply eighteen ovens, should it be advisable to enlarge the 
works to that extent. With the exception of the men employed in heating and managing the ovens, 
no professional bakers are required, ordinary laborers and boys being fully competent to every other 
part of the work. 

M. Lecompte De Fontainemoreau, of Finsbury, has patented certain improvements iu apparatus for 
kneading and baking bread, &c. The " apparatus for kneading" dough consists of a semi-cylindrical 
trough, within which is placed longitudinally an axis or shaft, to which are attached on the opposite 
sides two rows of radial arms, the arms on one side of the shaft being placed opposite the spaces be- 
tween those on the other side. The ends of the arms of each set are connected together by rods parallel 
to the shaft which carry short arms projecting inwards, and placed between the long arms. The 
shaft is driven by a winch handle, and the action of the arms when it is in motion, effectually kneads 
the dough coiitaiued in the trough. The " apparatus for baking " consists of a circular oven provided 
internally with a revolving table, on which are placed the articles to be baked ; and which table is made 
to rise or fail, as may be required, to change the temperature. The bottom of the oven is heated bj 



tubular flues, under the movable table ; the sides by vertical flues, which lead from the fire-place tr 
the top of the oven, where space is left for the heat to circulate over the whole of it. Above the top 
flue, which is formed by two plates of metal, the oven is covered with earth, except at one part, where 
is fixed a receptacle to contain water for the service of the kneading apparatus ; such water being 
heated by the flames, &c, passing through the flue on the top of the oven. A thermometer applied to 
the exterior shows the degree of heat, and dampers are provided for its regulation. 

The following improvements in bread and biscuit machinery are patented by Mr. Exall, of Reading. 
For kneading flour into dough he uses a hollow screw, or spiral bar of iron, revolving in a cylinder or 
tube. The materials to be kneaded are supplied by a hopper at one end of the cylinder, which is hori- 
zontal, and forced out at the opposite end through a mouth-piece of any suitable form of orifice. The 
kneaded dough, previously passed through a pair of roughing rolls, is placed on a feed-table, and sup- 
plied in a sheet of any desired thickness by a pair of rollers to a travelling web, which carries it 
successively under the operation of marking or stamping dies, and cutters, having a reciprocating verti- 
cal motion, by which the dough is stamped and cut into the form of biscuits, which are then transferred 
to the oven. When the biscuits are round and cut to waste from the sheet of dough, the apparatus is 
so arranged as to separate the detached fragments, and prevent their going into the oven with the 

A new form of oven is used, in which the baking is effected in the interior of a series of horizontal 
tubes, set like gas retorts above a fire, or in a flue, and open at either one or both ends, but provided 
with suitable doors for keeping the same closed during the operation of baking. 

BREAKWATER. A kind of artificial embankment, dike, or rampart, formed of large stones, and 
erected for the purpose of protecting the entrances of harbors, also roadsteads, from the effects of 
violent winds, by breaking the force of the waves of the sea ; the shipping, moored behind them, lying 
perfectly secure. 

The most celebrated works of this description are those of Cherbourg, in France, and Plymouth, in 

That of Cherbourg was the first executed, having been begun in the year 17S3: the building of the 
wall was commenced upon upright cones of timber, and each cone was intended to have been about 
150 feet diameter at the base, 60 feet at the top, and about 60 or 70 feet high, the depth of water at 
spring-tides, in the line in which they were sunk, varying from 56 to 70 feet; they were also intended 
to have been filled with stones to the top, and after allowing some time for settling, the masonry was 
intended to have been commenced upon them ; but a few of these cones only were constructed, when, 
in consequence of the difficulty of the undertaking, the whole was covered with large stones, thrown in 
at random. This breakwater is 10 feet above the highest tides, and has a roadway or platform 20 feet 
wide on the side next the shore, a parapet-wall being built upon it on that next the sea. 

The Plymouth breakwater was commenced in 1812. It is composed of blocks of stone, 1^ to 2 and 
3 tons weight, and consists of a central part, 1000 yards long; and two wings, each 350 yards long, 

Plan of Plymouth Breakwater. 

directed towards the sea, and forming angles of 15S° with the centre portion. A transverse section 
taken through the breakwater shows an average base of 290 feet, and the breadth at the top is 48 feet, 
with an average depth of water, at low spring-tides, of 36 feet ; the side next the sea is sloped in the 

£ectton of Plymouth Breakwater. — A A, high-water spring tides. B B, low-water spr 

D, the fore-shore. 

proportion of 1 perpendicular to 7 horizontal, and the side next the land is 1 to 5 ; these sides were 
not intended, originally, to have had so great a elope, but, in consequence of the violence of the waves 
during its construction, it was thought proper to increase them, as executed. 

The stone was raised in large blocks, some of which contained 10 tons, and -were thrown into the 
tea, in the direction set out for the breakwater, care being taken that the greater number were de- 
posited upon the outer slope. After a number of these large masses had been lowered, a smaller 
class of stones, quarry rubbish, rubble, and lime-screenings, were tin-own in to fill up the interstices, 
and close all the cavities ; these found their position, by the action of the sea, and the great mass be- 
came, as it advanced, perfectly wedged together. 


BREAKWATER. Fig. 5SG represents a form often given 
to the pavement of the glacis or sea slope of a breakwater. 
The stones should be of sufficient size to resist the action of 
the sea. 

BREAST. In mining, the face of coal-workings. 
BREASTS. The name given to the bushes connected 
with small shafts or spindles. 

BREAST WALL. A wall built up breast-high, as a par- 
apet-walL or a retaining-wall, placed at the foot only of a Section showins the Breakwater Glacis, 


BREAST WHEEL. A water-wheel which receives its motion from a stream of water flowing on to 
the breast or side of it, and then descending, bears by its weight upon the lower part of the wheel See 

BRICK. An artificial preparation of clay, sand, and ashes, burnt in a kiln, or clamp, and nsed for 
building, and for other purposes : good brick earth is also sometimes found in a natural state. A good 
brick is about SJ inches long, i± inches wide, and 2i inches thick, when burnt. 

Bricks appear to have been used for architectural purposes at a very remote period, as we 
learn from the Scriptures that the Israelites were employed to make bricks in Egypt ; and some 
of the most durable of the Greek and Roman mouuments which have come down to us, are wholly, 
or in great part, constructed of this material. La the East they bake their bricks in the sun ; the 
Romans used them crude, only leaving them a long time in the air to dry, about four or five 
years. In modern times, brick-making is nowhere carried to greater perfection than in Holland. 
where most of the floors of the houses, and frequently the streets, are paved with excellent and very 
durable bricks. Loam and marl are in England considered the best materials for bricks. The for- 
mer is a natural mixture of sand and clay, "which may be converted at once into bricks ; marl is a 
mixture of limestone and clay in various proportions. The neighborhood of London is remarkably 
adapted for the making of bricks, the soil of the whole surrounding country being clay at a certain 
depth, generally below a bed of gravel, and the bottom of the Thames yielding the sand which is used 
in this manufacture ; but great practical carelessness seems to pervade the whole business as conducted 
there. The following is a description of the process as it is usually conducted around the me- 
tropolis: The earth is dug up in the autumn, and suffered to remain in a heap until the next 
spring, that it may be well penetrated by the air, and particularly by the winter frosts, winch, by 
pulverizing the more tenacious particles, greatly assists the operations of mixing and tempering. In 
making up this heap for the season, the soil and ashes, or sand, are laid in alternate layers or strata, 
each stratum containing such a thickness as the stiffness of the soil may admit or require. In temper- 
ing the earth, much judgment is required as to the quantity of sand to be thrown into the mass, for too 
much renders the bricks heavy and brittle, and too little leaves 'hem liable to shrink and crack in the 
burning. The addition of sea-coal ashes, as practised about London, not only makes it work easy, but 
saves fuel, as when the mixture is afterwards sufficiently heated these bricks are chiefly burned by the 
fuel contained in the clay. When the brick-making season arrives, the heap is dug up, the stony parti- 
cles carefully removed, and the mass properly tempered by a thorough incorporation and intermixture 
of the materials, with the addition of as little water as possible, so as to form a tough viscous paste. 
If, in this operation, too much water be used, the paste will become almost as dry and brittle as the soil 
of which it is composed. In order more effectually and regularly to mix the loam and ashes, it is now 
generally performed in a sort of mill, named a pug-milL Tins consists of a large tub or tun, fixed 
perpendicularly in the ground, and having an upright bar, fitted with knives, placed obliquely. The 
upright bar is turned by a horizontal lever, to which a horse is attached, and the soil being put in at 
top, is, by the revolution of the knives, forced through a hole in the side of the tub near the bottom, 
whence it is removed to the mould-table, which is placed under a moveable shed, and is strewed witli 
dry sand. A girl rolls out a lump somewhat larger than the mould will contain. The moulder receives 
this lump from the girl, throws it into his mould previously dipped in dry sand, and with a flat smooth 
stick about 8 inches long, kept for the purpose in a pan of water, he strikes off the overplus of the soil ; 
he then turns the brick out of the mould upon a thin board rather larger than the, brick, uprn which it 
is removed by a boy, who places it on a light barrow of a particular construction, which being loadec 
with a certain number of bricks, they are sprinkled with sand, and wheeled to the hacks. The hacks 
for drying are each wide enough for two bricks to be placed edgewise across, with a passage between 
the heads for the admission of the air, to facilitate the circulation of which the bricks are usually laid 
in an angular direction. The hacks are usually carried eight bricks high ; the bottom bricks at the ends 
are usually old ones. In shower}' weather the hacks must be carefully covered with wheat or rye straw, 
unless sheds or roofs be built over the hacks, as is done in some parts of the country, but in London 
this is impracticable, from the very great extent of the grounds. In fine weather the bricks will be 
ready for turning in a few days, in doing winch they are reset more open than at first, and in six or 
eight days more they will be ready for burning. In the vicinity of London bricks are commonly burned 
in clamps. In building the clamps, the bricks are laid after the manner of arches in the kilns, with a 
vacancy between every two bricks for the fire to play through. The flue is about the width of a brick, 
carried straight up on both sides for about three feet ; it is then nearly rilled with dry bavins or wood, 
on which is laid a covering of sea-coal and cinders, (or, as they are termed, breeze ;) the arch is then 
overspanned, and layers of breeze are strewed over the clamp, as well as between the rows of bricks. 
When the clamp is about six feet wide, another flue is made in every respect similar to the first. This 
is repeated at every distance of six feet throughoat ihe clamp, which, when completed, is surrounded with 
old bricks, if there be any on the grounds, if not, with some of the driest of the unbaked ones reserved 
"or the purpose ; on the top of all, a thick layer of breeze is laid. The wor»i is then kindled which seta 



fire to the coal ; and -when all is consumed, which will be in about twenty or thirty days if the weather 
be tolerable, the bricks are concluded to be sufficiently burned. To prevent the fire burning too furiously, 
the mouths of the flues are stopped with old bricks, and the outside of the whole clamp plastered with 
clay ; and against any side particularly exposed to the rain, t£c, screens are laid, made of reeds worked 
into names about six feet high, and of a width to admit of being moved about with ease. This is the 
mode of manufacturing the ordinary descriptions of bricks ; but the superior sort, termed washed malms 
or marls, are tempered with greater care and attention. For this purpose a circular recess is built about 
four feet high, and from ten to twelve feet diameter, paved at bottom, with a horse-wheel placed in its 
centre, from which a beam extends to the outside for the horse to turn it by. The earth is then raised 
to a level with the top of the recess, and forms a platform for the horse to walk upon. Contiguous to 
the recess a well is formed for supplying the recess with water, winch is raised by a pump worked by 
the horse-whecL A harrow made to fit the interior of the recess, thick set with long iron teeth, and 
well loaded, is chained to the beam of the wheel to which the horse is harnessed. The soil prepared 
in the heap in the usual manner is brought in barrows, and distributed regularly round the recess, and 
a quantity of chalk is added, and a certain portion of water; and the horse being set in motion, drags 
the harrow, which forces its way into the soil, admits the water into it, and by tearing and separating 
the particles, not only mixes the ingredients, but also affords an opportunity for stones and other heavy 
matters to fall to the bottom. Fresh clay, chalk, and water, continue to be added until the recess is 
full. On one side of the recess, and as near it as possible, several hollow square pits are prepared about 
IS inches or 2 feet deep. The soil, reduced to a kind of liquid paste, is discharged from the recess by 
a sluice, and conveyed by wooden troughs to the pits. In these pits the fluid soil diffuses itself, settling 
of an equal thickness, and remains until wanted for use, the superfluous moisture being drained or 
evaporated away by exposure to the atmosphere. The remainder of the process is the same as for the 
common sort of bricks. In the country, bricks are always burned in kilns, whereby much waste is prevented, 
less fuel is consumed, and the bricks are more expeditiously burned. A kiln is usually 1 3 feet long by 1 
feet 6 inches wide, about 12 feet in height, and will burn 20,000 bricks at a time. The walls are about 
14 inches square, and incline inwards towards the top. The bricks are set on flat arches, having holes 
left between them resembling lattice-work. The bricks being set in the kiln, and covered with pieces 
of broken bricks or tiles, some wood is put in and kindled to dry them gradually; this is continued till 
the bricks are pretty dry, which is known by the smoke turning from a darkish to a transparent color. 
The burning then takes place, and is effected by putting in brushwood, furze, heath, faggots, &c. ; but 
before these are put in, the mouths of the kiln are stopped with pieces of brick called shinlog, piled 
one upon another, and closed over with wet brick-earth. This shinlog is carried just high enough to 
leave room sufficient to thrust in a faggot at a time ; the fire is then made up, and continued till the 
arches assume a whitish appearance, and the flames appear through the top of the kiln, upon which the 
fire is slackened, and the kiln cooled by degrees. This process is continued, alternately heating and 
slackening, till the bricks are thoroughly burned, which is usually in the space of forty-eight hours- 
Many attempts have been made of late years to supersede, by the aid of machinery, a portion of the 
manual labor now employed in the manufacture of bricks. 

BRICK-MACHINE. Fig. 587 is a representation of Stephen Ustick's, for Moulding and Pressing 
Binds from unterapered clay 


haft D an 

A A, frames, t 

B C and the 

B C, cams which give the pressure to 

the outer pistons. 

D, centre shall on which the wheel of 
moulds revolves. 

E, cam-wheel on the centre shaft D, 
which gives the pressure to the inner 

F, cam-wheel on side shaft-, above the 
cam-wheel E, which gives motion to 
the fillers. The view of this cam- 
wheel is obstructed by the receiver. 

O, the pinion on the driving-shaft. 

G, revolving wheel on the shaft D, hav- 
ing pairs of parallel arms to which 
the moulds are bolted, and between 
which the pistons slide. 

H, the moulds. 

1 1, pistons which condense the clay. 

K, the fillers which supply the moulds 
with clay. 

L, the hoppers above the fillers. 

M, a light cam, which brings the outer 
piston out of the mould after tho 
brick is pressed, while the inner one 
is thrust through the mould, carry- 

of the cam-whei 

N, a perpendicular cam which operates 
the plunger O, to discbarge the bricks 
from the pistons. 

P P, cams which bring the pistons into 
the moulds. 

Q, annular receiver, into which the clay 
falls from the pulverizer. 

R, openings in the bottom of the re- 
ceiver communicating ivith the hop- 
pers L. 

S, scraper which fills the hoppers 



After the first pressure is given to the clay, which commences when the outer piston is at the front 
end of the cam B, the air is let off of the brick by the filler, (the front end of which is a false top to tho 
mould,) moving inwards, leaving the upper part of the brick bare for the condensed air to escape ; it 
then moves back to its place before the piston reaches the back end of the cam C, and then the second 
pressure is given to the brick, without any loss of time, as a brick is made in each mould in every rev- 
olution of the wheel. 

From the full explanation of the different parts of the machine, and their functions, and by reference 
to the figure, it will readily be seen that it is simple in its construction, as all the motions to the pistons 
and fillers are given by stationary cams as the wheel of the mould rotates. The pressing cams give a 
powerful progressive pressure — the same in effect as that given by toggle-joint levers. 

Fig. 588 is a representation of Messrs. Choice and Gibson's brick-making machine, a a a a is an 
upright frame, with cross beams at top and bottom ; b c are two vertical shafts, carrying two hori- 
zontal spur-wheels d and e , the teeth of which take into one another ; these are put in motion by the 
horse-6haft yj or any other convenient power. Near the bottom of the shaft J, is fixed a large cast-iron 
collar a, having three deep mortises ; into each of these the end of an iron arm A is fitted, with a bolt 

Dassing through them to form a centre, as in a hinge-joint. To the other extremity of each of the arms 
It is firmly fixed, by screw-bolts, a cast-iron mould-box ?', having three divisions for three bricks, in -which 
work three stocks or false bottoms, having upright bolts passing through holes in the top. By the rev- 
olution of the shaft, these mould-boxes, with their arms, are successively earned up and over the 
risers k k k, which form circular curves in the plan, and appear so in the perspective, but are in real itv 


inclined planes. At I, near the bottom of the shaft, is a small bevelled wheel, -which actuates a pinion 
fixed on the spindle of the drum-wheel m that passes under the floor of the machine ; an endless strap 
passing round the drum m, and another placed at the required distance, continually carries the bricks 
forward to their destination as fast as they are made, and deposited upon it. o is a crank or lever, 
attached by a joiut to the framing, as shown, at the upper end of winch is fixed a roller ; by the revolution 
of the wheel above the three circular bars or cams, rrr, attached to the wheel, successively act upon 
the roller, and depress the crank o, which first raises the rod and weight q, and afterwards, as soon as the 
crank is relieved of the pressure, allows it to drop and strike the mould-boxes, by which the bricks are 
discharged out of them, s is a box of cast-iron, containing water, into which the mould-boxes dip ; t is 
a cushion, upon which they next fall in succession, by which the superfluous water is taken off; and,; is 
a box of dry sand, into which the mould-boxes afterwards fall, then- surfaces beaming in consequence 
slightly coated with sand previous to becoming charged with clay. The horizontal wheel c worked by a 
actuates the shaft c bearing the knives in the pug-mill. At the lower end of the shaft c is fixed the 
large circular revolving bottom-plate «, the periphery of which being furnished with teeth or cogs, as 
shown, take into the teeth of a circular revolving plate v, over which, as the mould-box passes, the Tower 
surface of the bricks becomes smoothed. At a- is a small frame, working up and down in a casing, with 
a pulley and counterbalance weight, like a sash window ; it is raised by the crank y as each mould-box 
passes, when three little boards are placed across the frame by a boy, for the reception of the bricks. 
When these are deposited by the means described, the frame chops below the level of the endless strap 
n ; the latter then receives them, and carries them off to their destination. At z is fixed a flat box, 
which acts as a gage to regulate the thickness of the stratum of clay revolving upon the bottom plate n 
of the pug-mill. The operation of tins machine is as follows : the clay being worked in the ordinary 
manner through the pug-mill, it passes out at the mouth, (not shown, being on the opposite side,) from 
thence under a flap wluch partly regulates the quantity on the bottom plate, and next under the gage, 
which determines it precisely. A mould-box having passed over the highest inclined plane or riser k, 
first falls on the stratum of clay, and chops out three bricks, filling the moulds therewith bj' the false 
bottoms rising up to the determined point from the pressure of the clay against them ; the moulds, with 
the bricks in them, then slide over the polishing plate r, (which is kept wet b\ T water constantly dripping 
upon it from a tub ;) from thence the moulds pass on to the frame x, when the weight q strikes against 
the protruded bolts of the false bottoms, and pushes out the bricks upon the boards on the frame ; the 
frame then descends two or three inches by their weight, and delivers the boards upon the endless strap, 
which, being constantly in motion, carries the bricks away to be deposited on the hacks. The mould-box 
being discharged, is then carried upon its roller up the fir:it riser Tc, drops into the water, thence rises 
again, falls upon the cushion, next into the sand-box, whence ascending again, the highest inclined plane 
being duly prepared, it falls again upon the bottom plate of the pug-mill, and chops out three more 
bricks, during wluch period eacli mould-box has operated in a similar manner. 

We shall now proceed to describe the brick-making machinery invented by Mr. Leahy, and erected 
by him for the Patent Brick Company; it is represented in the succeeding figure, a is the main 
horizontal shaft in direct communication with the steam-engine or other first mover ; b is a hopper- 
formed vessel, technically termed the pug-mill, in wluch the clay and other materials are tempered and 
mixed up : it is for this purpose furnished with cross iron bars, or blades of steel ; part of these are 
firmly fixed to the hollow vertical shaft c, and the remainder bolted to the sides of the pug-mill, and 
they are so arranged, that those fixed to the shaft cut in as they revolve between the others. The 
clay is delivered into the hopper or pug-mill by an endless chain of buckets, (in the same man- 
ner as ballast is raised;) it is then cut up and tempered by the knives and bars in the pug-mill, and 
gradually descending, it falls, or rather is forced by the superincumbent pressure upon the circular 
inclined plane d, which consists of a single thread or spiral turn of a very large screw, occupying the 
whole internal space of the lower cylindrical end of the mill, where it is exhibited in section. This 
screw or circular inclined plane is fixed to the central shaft passing longitudinally the hollow shaft, and 
a slow reversed motion is given to it, by means of an intermediate wheel acting upon pinions in the 
upper part of the frame. The blades on the hollow shaft revolve in the pug-mill at the rate of fifteen 
turns in a minute, grinding and dividing the materials much more completely than in the ordinary mode 
of brick-making. In this attenuated state the materials are forced upon the circular inclined plane ol 
the screw, and as tliis slowly revolves in a contrary direction at the rate of five turns in a minute, it 
takes hold of the clay, (by a peculiar adaptation not easily described.) and forces it out of the mill in 
a very compact state, into a receptacle below : of this, one side is alwaj's in immediate contact with the 
moulds, and those two sides wluch are at right angles to the former side are closed by iron cheeks, 
between which the lever or forcing flap n acts by pressure, and fitting closely, prevents the escape 01 
the clay, -so that it can only pass into the moulds. These moulds are placed round the periphery of a 
circular frame e, made of fiat iron rings, fixed upon bars or spokes, and turning upon a fixed shaft. 
There are twenty-five of these moulding-boxes in one circle ; but as the frame e may be of any breadth, 
it may contain twice twenty-five or tlnice twenty-five on the circumference of the C3 T linder, provided 
that the engine is capable of affording sufficient power or force to cut or mould so many bricks at each 
revolution. Each moulding-box is furnished with a false or moveable bottom, to which rods are 
attached, for the purpose of pushing out the brick when moulded, and drawing back the bottom to its 
place to receive a fresh portion of the clay. The manner in which these operations are performed is 
extremely simple and ingenious. The ends of each of the moulding-box rods are bent at right angles, 
and an eccentric piece / is so fixed, that, as the moulds revolve, and at the moment that the surface 01 
each is covered by being in contact with the clay, it gradually draws back the false bottom, and with 
it the clay, which is also urged on by the circular inclined plane d ; and to render the bricks solid an. 1 
compact, a powerful pressure is applied to them by means of the flap forcer n, to which a backward 
and forward motion is given by the thrusting of a rod attached to a revolving crank. The mouldinsr- 
boxe<;. immediately they are thus filled, are subjected alternately 'o the action of a .steel scraper, which 



levels and smooths their surface, and is made to operate by the pressure of springs. The bricks, now 
completely formed and fast in their moulds, pass downwards in their revolution, which brings the ends 
of the rods under the operation of a cylindrical roller, with grooves made round it at equal distances; 
into these grooves the ends of the rods successively pass, which, in their revolution, force out the rods, 
and thereby push out the bricks from the moulds on to boards placed underneath to receive them. 
The bricks thus made are carried forward to the hacks or drying-house, upon an endless web or chain i i, 
to which a continued motion is communicated by the revolution of the two polygonal drums or wheels 
fc I; placed at the requisite distance asunder. The upper part of the engraving shows a side elevation 
of the machine, and the lower part a section of it ; and although these views serve to give a general 
idea, of the construction of the apparatus, it has been impracticable to show the gearing by which tlw> 

nnnnnri i 




several motions are produced ; we w T ill therefore attempt to describe it as follows : — Upon the horizontal 
shaft a. (which makes 2§ revolutions per minute.) is fixed a toothed, bevelled wheel, which drives a 
bevelled pinion on an upright shaft, (not shown ;) nearly at the top of this a spur-wheel is fixed, which 
works into a pinion fixed upon the upper end of the hollow shaft c, which carries the knives or blades 
in the pug-mill. Upon the upper end of this upright shaft is also fixed a pinion, which works into an 
intermediate pinion turning upon an axis. This intermediate pinion acts upon another pinion affixed to 
the internal shaft, communicating a slow and reversed motion to it, and also the circular inclined plane 
affixed to it ; at the lower end, on the main horizontal shaft, is fixed a spur-wheel m, which gives 
motion to the crank and to the flap forcer connected to it. o, in the separate figure, gives the form 01 
the shelves comprising the drying apparatus, — Mr. Leahy proposing to dry bricks either by flues or by 
steam, instead of ranging them in hacks exposed to the variations and inclemencies of the weather, — by 
which means it is presumed that the bricks will be rendered dry enough for burning, either in kilns or 
clamps, in a much shorter time than in the common method, and the process may be carried on in 
winter as well as in summer. If drying by flues be resorted to. a drying-house must be furnished with 
proper stages, and shelves must be provided. Around and across the lower part of these, flues framed 



either of bricks or cast-iron are to be placed, through which flame or heated air is to be conveyed. _ In 
drying by steam, the vapor is conveyed from the boiler through cast-iron pipes throughout the drying 
house, and boards are arranged upon stages, (similar to those in Fig. 590.1 so as to leave intervals 
between the rows of bricks, and to prevent their touching one another. 

Nash's Patent Brick-making Machinery. 

This invention, which we have now to describe, is not the only one, we believe, that has been brought 
into successful operation. The leading features of Mr. Nash's mechanism consist in the application o 

separate or detached moulds of a particular construction to a series of mould-boxes, which are consecu- 
tively brought into action ; in the employment of heaters, placed in contact with, or contiguous to, the 
fresh bricks, during the process of their being moulded ; and in lieu of sand, which is generally used to 
prevent the adhesion of the bricks to the moulds, employing elastic absorbent substances, such as cloth 
saturated with water. In the subjoined engravings. Fig. 591 represents a front elevation, and Fig. 592 
an end elevation of the principal parts of the machine. A vertical shaft a is made to revolve in the 
cylinder or pug-mill 6, by any adequate force acting upon the bevelled wheel c. A number of broad 



steel or iron blades ddd are attached to the shaft a, their surfaces being set at such an angle as will cause 
them, during their revolution, to pass nearly in contact with the edges of two other sets of knives eee, 
fixed on opposite sides of the cylinder, by which means the clay and other materials with which the 
mill is charged are tempered and amalgamated, and then forced into the hopper /, fixed to the lower 
extremity of the pug-mill. This hopper is divided into two equal chambers by a vertical blade or 
knife, which separates the materials into equal portions, which are supplied to the moulds in a compact 
state. The moulds are lodged in rectangular cavities at equal distances in the periphery of two 
polygonal drums gh; these cavities are marked 1 to 12. To one face or side of the drums are 
attached two toothed wheels, gearing into each other so as to revolve in opposite directions when 
motion is communicated to one of them. 
These wheels lying at the back of Fig. 591 
cannot be seen, but one of them is shown 
at i in Fig. 592. The moulds, after being 
filled with the plastic material, are pushed 
out n>jm their recesses by means of pistons 
at >n in, easily fitting the recesses, and 
sliding upon parallel rods fixed to the rims 
of each drum. To each piston is attached, 
by a short rod, a cross-head, sliding upon 
the parallel rods, and having at each end 
small anti-friction wheels pp, which, by the 
motion given to the machinery, come in 
contact with a larger wheel g, placed ec- 
centrically, which thus raises the pistons, 
and the moulds which he upon them are 
then removed by hand and emptied. Dur- 
ing this latter process the emptied mould- 
receiver will have passed over the centre 
of the eccentric wheel q, and the piston 
will be descending when the attendant 
places the emptied mould in its former sit- 
uation, to be filled again from the hopper 
as it passes under it. Between each of 
the rectangular mould-boxes are formed a 
series of wedge-shaped boxes, termed by 
the patentees "hollow sectors," into each 
of which is placed a red-hot iron, the object 
of which is to expel the superfluous moist- 
ure from the newly-formed brick, <£c, in 
order that the manufacture may be con- 
ducted in the winter as well as the sum- 
mer. These irons are heated in the kiln- 
fires. The axis of the polygonal drums re- 
volve in plummer-blocks, supported upon a 
strong frame s; but as the polygonal drums 
revolve in close contact, the plummer- 
blocks are free to slide in grooves in the 
frame, and the wheels are kept in contact 
by the action of strong helical springs t, 
which press against the plummer-blocks, 
the other end of the springs abutting 
against a regulating screw. In the middle 
o^ and underneath the horizontal frame & 
is fixed a knife w, (supported in its place 
by a spiral spring,) which separates the 
whole or a portion of the superfluous ma- 
terials from each mould, as the Latter passes 
over the edge of the former. As some re- 
dundancy of material may still be left after 
the operation of the knife u, the exposed 
surface of the moulds in motion undergoes 
a similar treatment from two other knives 
v v, fixed to the foundation plate to of the 
machine. A trough or cistern k k, contain- 
ing water, is placed under each of the 
drums, the lowest sides of which come in 
contact with a cylinder y, covered with 
strong coarse cloth or other suitable absorbent substance, which, as it revolves, takes up the water and 
delivers it to the moulds as before mentioned. These cylinders are mounted on elastic bearings, and 
derive their motion from pinions on their axes, actuated by the toothed wheels on the drums. In the 
centre of the foundation plate there is a cavity, or pit, for the reception of the superfluous clay or other 
materials, which are removed at pleasure. The pug-mill has a door in it, for the convenience of cleaning 
it out when requisite ; and the whole of the upper part of the machine is supported by throe columns 







°( c 

— - . _J 






2 2 2. The polygonal drums are driven by a set of wheels lying at the back of Fig. 591, and therefore 
in that figure shown by dotted circles. No. I. is a band-wheel, which drives, by a pinicn II, the two 
wheels III and IV, on the axes of the driving gearing, into each other, and turning in opposite directions. 
Those two wheels must have involute teeth, as their point of contact becomes variable by the move- 
ment of the axes of the drums. In case of negligence on the part of the boys, or other attendants ol 
the machine, in not removing the bricks or tiles after the moulds containing them have passed the 
centre of the eccentric wheel, they fall back into their former position, and pass round to the place oi 
delivery, as before, without any damage whatever being done to the machine. 

Having explained the general arrangement and operation of the machine, there remains to be 
described the construction of the detached moulds. Fig. 598 represents a side view, and Fig. 591 an 
end view of one of these. The ends 
of the mould 18, 18, are made of 
wood, plated at the edges with iron, 
and fastened on by screws, as seen 
in Fig. 593. The bottom 19, is also 
of wood, but cased in a strong frame 
of cast-iron, and its two extremi- 
ties are jointed to the ends 18, 18, 
so as to open only a little way, for 

allowing the brick to separate freely " z' 

from it upon inverting the mould. 

This effect is facilitated by lining the interior of the mould with cloth, which, although constantly in a 
wet state, admits ah to pass through its interstices when the clay is forced into the mould, so that 
when the brick is afterwards forced out, the moisture of the cloth, and the spring of the confined ah, 
delivers the brick uniformly clean, without the adhesion of any clay. It will be observed that the two 
ends 18 of the mould have each a cavity; these cavities receive the fingers of the workman when he 
takes hold of the mould, which he afterwards inverts, drawing back the ends 18 at the instant, and 
pressing with his thumb upon the screw-heads 21,21, the other ends of which arc attached to a plate 22 
underneath the cloth lining of the bottom, as shown by dots, causing the brick to be immediately 
disengaged. The two sides of the brick not included in the detached mould are formed by the par- 
tition between the mould-boxes and the hollow sectors. The forms and dimensions of the detached 
moulds are varied according to the nature of the articles to be produced therefrom. For adapting the 
machine to make tiles, or other articles of a greater length than a brick, two moveable blocks, which 
usually lie inside the hopper, to contract its lower dimensions, are taken out. In the making of dram 
tiles, and other articles having cavities within them, jointed horses or cores are employed ; the plastic 
matter is forced around them by the action of the machine in the same manner as in forming a brick, 
'and the subsequent operations are also the same, except that in the removal or delivery of such tiles 
from their moulds, suitable adaptations are made to prevent their being pressed or even touched by the 
hand. The annexed Fig. 595 exhibits 
another arrangement employed by Mr. 
Nash for making flat tiles, flooring tiles, 
Ac., of any required breadth and thick- 
ness. This cut only represents the 
lower part of the machine, the upper 
being the same as in the previously- 
described apparatus. To the bottom 
of the pug-mill is fixed a funnel-shaped 
hopper 23, the materials in which, after 
being forced through a mouth 24, 
formed of the required shape, are re- 
ceived upon boards 25, and when cut 
to the proper length, are removed to 
sheds for drying. In order to equalize 
the surface of the clay after it has come 
out of the hopper, a roller 26, turning 
in bearings on a curved arm, which is 
fixed to a hinge-joint, gives to the ma- 
terial any pressure that may be re- 
quired, by loading it accordingly. The 
dotted lines 27, 27, in the same figure, 
exhibit another funnel-shaped hopper, 
for the purpose of making pipes or 
tubes, by means of a centre core 28, 
between which and the cylindrical con- 
tinuation of the hopper, the material is 
forced by the action of the pug-mill, 
and produces a tube, which, after having 
made a certain length of, is cut off, the 
tube being turned round, to render the 
inside smooth previously to its being 

removed. The patentee states that this machine may be used with either one or two horse power ; 
that when used with one horse power, the product is about 700 per hour, or 8000 per day ; to do which 
requires the services of two men and eight boys, occasioning an expense not exceeding two shillings and 


sixpence per 1000. "With two horse power employed, the production is double, or 16,000 per day, but 
the quality of the bricks, which the editor has seen, is equal to those which are usually finished by 
grinding the surfaces by hand. The saving of labor in the production is about two shillings per 1000 ; 
but the quality rendering them worth five sliillings per 1000 more in the market, the advantage of 
making by the machine, where good bricks are required, is equal to seven sliillings per 1000. 

BRICKS AND TILES, Machinery for the manufacture of. The application of machinery to the 
fabrication of bricks has met with considerable opposition in the diversity of physical and chemical con- 
ditions of the earths used. Thus, in some localities the clay has more tenacity and aluminous properties 
I ban in others ; the mechanical powers sufficient for the last would be useless in the first. 

As early as 1S35, M. Terrasson had constructed a machine surpassing all previous oues in simplicity 
A frame, having wires stretched across, cuts into bricks the earth which has been compressed between 
a roller and planks. 

M. Carville has invented a machine which simultaneously bruises and divides the earth, moulds and 
Lhrows off the bricks ; it may be applied to the fabrication of tiles and other earthen ware. 

Description of M. OarviUe's Machine, Figs. 590 to 004. 

Division and kneading of the Earths. — The earths used are clays, requiring sometimes sand or 
aluminous compounds. The mixture is the most difficult part in all the process of brick-making. To 
this end M. Carville uses a cylindrical barrel A, with a fiat bottom; its upper pait is opened in order to 
introduce the material. An axis B, also vertical, to which a rotary motion is imparted by a horse har- 
nessed to the beam C, through the medium of the cast-iron socket a, (see Fig. 596, which is a vertical 
section through the middle of the machine.) This axis rests against two pillows, one adapted to a beam 
4, which unites the opposite sides of the machine, and the other upon an inferior cross-beam. This axis 
is provided with several flat iron branches d, which being fixed perpendicularly to the axis, their faces 
have an inclination of 45°. On these there are sharp-edged knives, to divide and knead the clay during 
their rotation ; thus the earth is well divided before reaching the inferior part of the barrel. The 
branches ef stouter than the former, but without knives, are attached at the very extremity of the axis, 
and receive from it a rotary motion, during which they press against the earth, forcing it out through 
the orifice g. The size of tliis orifice depends on the quantity needed to fill the moulds ; the iron sliding- 
door h regulates this orifice. 

This method for dividing and kneading is applied to the fabrication of earthen ware, porcelains, etc. 

Moulding and casting off the Bricks. — It is specially in these functions that M. Carville's machine 
excels all others. He uses a series of moulds in cast-iron, forming an endless chain D, constantly moving ; 
these moulds successively pass beneath the aperture through which the moistened earth is pressed, in 
order to receive it. Each link forms a rectangular frame, composed of four moulds, which have the 
precise dimensions of the bricks. Figs. 597, 598, 599, show a plan and transverse section of this chain. 

Two wheels, with each four arms E, are situated on either side at the extremity of the apparatus. 
The iron bars i support the limbs and impart to them the movement of rotation communicated by the 
spur-wheel F; the arrows indicate the direction in which they are to move Fig. 596, so that the moulds 
are carried under the roller G after they are filled with earth. 

This roller is of cast-iron, turning round a horizontal iron axis, set in motion by the beam C. Its office 
is to compress the earth in the moulds as it is received from the barrel. But as these moulds have nc 
bottom, a moveable flooring is adapted to them to serve as such ; it is made of strong sheet-iron j, the 
pieces approaching each other at distances proportional to the length of the bricks, and hooked to an 
endless chain passing over the rollers k ; one of these rotates, giving to the chain a motion equal to the 
speed of the moulds. These must be nearly horizontal, when they pass beneath the barrel ; to give 
them this direction, a number of wooden rollers H support the iron plates. The axes of these rollers are 
of iron, freely turning on pillows, Fig. 600. 

The clay being thus moulded and pressed, soon meets the blades /, made of steel or cast-iron, which 
shave the two horizontal and parallel faces of the moulds, levelling and polishing the bricks. 

The clay is prevented from adhering to the surface of the rollers by the water slowly falling from the 
vessel I. 

A wooden hopper J, containing fine and dry sand, sprinkles the bricks as they pass beneath / ; a small 
fluted cylinder m, is adapted to the base of the hopper to allow the sand to come out — but in small 
quantity ; this cylinder is rotated by means of a pulley and strap, or a small endless chain. 

As soon as the bricks have passed the polisliing blades, they are taken out of the moulds. This is 
ingeniously done by the simple process of M. Carville. Two pieces of cast-iron K, having a superficial 
dimension equal to that of the section of the mould, which they completely fill, are attached to a single 
vertical beam L, which is suspended to another beam M, the other extremity of which being balanced 
by a counterpoise, this is prevented from idling by a board N. 

To the axis of the beam il a vertical branch n is adapted ; this receives a movement of oscillation, 
depending on the speed of the endless chain of moulds. To tliis end, this last is provided with little 
knobs o, Fig. 598, which meet and push successively a horizontal lever r, Fig. 599, fixed to the vertical 
axis g. To the superior part of this axis is attached the pulley r, Fig. 596, to the circumference of which 
is hooked the small chain O, whose other extremity is fastened to the pulley r', freely rotating round 
the iron pin P. 

Thus when one of the knobs o is in contact with the inferior lever p, it pushes it in the direction ol 
the chain, causing the vertical axis q to turn ; the pulley attached to q turns also, carrying along the 
chain (.*, and since the extremity of the vertical branch n is engaged in one of its links, it is drawn by 
it : therefore the axis carrying it oscillates, and also the beam 11 ; L descends, pushing the lumps K into 
the two corresponding moulds, tlirusting the bricks on a moveable floor/. The weight attached to tho 
beam M causes L to rise, as soon as the lever is no 'onger acted on by the eminence o. 




To bring back to its original position the beam L, a cord is attached to its lower extremity, passing 
through the pulleys * s', and having a small counterpoise fastened to its other end. 

The chain, going all the time, plunges into a reservoir of water Q, which extends its whole length, to 
wash the moulds. Following the direction indicated by the arrows, it passes under the hopper R, where 
the moulds are sprinkled with sand before reaching the barrel. 

The second moveable flooring f, which receives the bricks, is composed of small plates forming an 
endless chain ; parallel rollers, such as H', placed in a different direction from the first, support this 
chain. Their iron axes are moveable in pillows resting against oak beams S. 

This flooring moves only when the beam L rises. The teeth o raise successively, a short lever p', 
which is attached about the middle of the short vertical axis q' ; to this is adapted a second lever »', fixed 
to a small horizontal beam t, which communicates through a rope with the pulley u. Thus, as soon as 
a tooth acts on p', its axis oscillates, and its inferior lever n forces the flooring f to advance a distance 
equal to the breadth of the two bricks. The small rope passing through u has a counterpoise to bring 
back the levers to their original position. 

The bricks being taken off without any handling, are put up to dry. The plates are set back to the 
chain J', on the side opposite to that on which the bricks were. 

Description of the Machine of J/. Capouillct, Figs. 605, 606, 607. 

This machine consists of two cast-iron cylinders, performing the office of rollers ; one is perfectly 
smooth, the other is pierced over all its surface with cavities, the dimension of which depends on the 
size of the bricks to be made : pistons are made to fit into these cavities. These pistons receive an 
alternative movement equal to the thickness of a brick. 

Construction- of the Cylinders The first cylinder A is solid and smooth; its diameter is 7 -31 feet. 

and its breadth is 7 - 47 feet. It has an axis of wrought-iron B, turning in pillows with screws a. It 
receives its motion from the second cylinder, through a straight-toothed wheel C, whose inner diameter 
is precisely that of the external cylinder. 

The second cylinder A' is of the same dimensions with the first, but whose circumference contains a great 
number of rectangular cavities, having only 0039 feet between each, and of sufficient depth to contain 
each the thickness of a brick and of a metallic piston 6. It has also a horizontal axis of wrought-iron 
B',.of equal length with the preceding. It also is provided with an axis C of equal diameter with C. 
with which it is engaged ; the pinion M communicates motion to it. 

The pistons o are rectangular, their dimensions in length and breadth being equal to the bricks ; 
they are free in the cavities, but closely fitting : a cylindrical rod is attached to them. 

Moulding tue Bricks. — The clay being prepared, is brought into a rectangular box D, extending 
as far as the two cylinders, between which the earth falls and is carried away by them. The quantity 
is regulated by a slide adapted to the box, whose height must not be less than 6'50 feet. By its side 
is placed a hopper E, containing dry fine sand to be sprinkled on the cylinder A' before the earth enters 
its cavities. The spout F regulates the direction of the sand ; to it an oscillating motion is imparted by 
the spokes c. 

The clay, falling between the two cylinders from the box D, is pressed into the cavities of A', filling 
them in succession with so much more ease as the pistons are pushed in. These pistons had previously 
been forced in by the cog, which is furnished with the circumference of a strong cast-iron disk G, situated 
at the right of the cylinder, and having an iron axis. These cogs are disposed as in a cog-wheel, and 
engaging into the cavities of the cylinder, they push the pistons within the cylinder. 

An eccentric of cast-iron H is contained within A', freely turning round on its axis, in order to force 
the pistons from within out, thus forcing the bricks away. The curve of this eccentric must be calcu- 
lated to give the pistons play only the thickness of a brick. Fig. 605 gives an external elevation of the 
apparatus, and also a part of the vertical section, showing the disposition of the pistons. 

Two scrapers d d, adapted to iron levers, which oscillate round the common axis/, and which have 
counterpoise e e\ serve to keep the surface of the cylinders smooth and clean. 

Transportation of the Bricks. — The horizontal boards I, receive the bricks as they are forced out oi 
the moulding cylinder ; they are moved with a speed somewhat greater than the cylinders, in order to 
leave a small space between the bricks. Their direction is from left to right. 

These boards are carried by small cylindrical rollers J of cast-iron, the axes of which rest on collars g', 
pinned on the sleepers, as seen in the horizontal section, Fig. 607. The toothed-wheel k, in which an 
endless chain k is engaged, transmits to them the motion communicated to it by the wheel which is 
placed on one of the rollers, to which the small pinion L is adapted. This last is engaged in the prin- 
cipal pinion M, whose axis is turned by the prune mover which may be a hydraulic wheel, a steam- 
engine, or a horizontal beam turned by a horse. 

Two brick-making machines much in favor in England, are Ainslie's and Hunt's. The latter has 
been extensively used in the execution of large contracts : it consists of two cylinders, each covered with 
an endless web, which are so placed that they form a sort of hopper on their two upper cylindrical sur- 
faces, the ends being enclosed by two iron plates. The tempered clay is thrown into this hopper, and 
at the lower part it acquires the form and dimensions of a brick. Beneath is worked an endless chain, 
by the movement of the cylinders, and at various marked intervals are laid the pallet-boards under the 
hopper ; the clay is brought down by a slight pressure, and enters a frame, which has a wire stretched 
across it, which projects through the mass, and cuts off the requisite thickness; this is immediately re- 
moved by the forward motion of the endless chain, and this operation is renewed as often as a new pal- 
let-board is advanced under the hopper. This machine produces about 1,200 bricks per hour, and is 
worked by two men and three boys. By this plan less pressure is given than in most machines, conse- 
quently the bricks are less difficult to dry equally. 

Machine-made bricks are smoother, heavier, and stronger than other bricks, but they do not adhere 
so well to the mortar, and are more difficult to dry well than those made by hand. 



is a plan of the machine. 

Fig. 609 is a side elevation, -with one of the propelling wheels removed. 

Fig. 610 is an end view of the mould-cylinder. 

Fig. 611 is a transverse vertical section of the machine, seen from the back, showing the 
cylinder in longitudinal section. 

Fig. 612 is a transverse sectional elevation of the mould and pressing cylinders in part, with 
attached-, appearing as in operation. 

■ " COS. 


Fig. 613 is a view in detail of a grooved channel and cam, used in working the followers. 

The same letters of reference denote similar parts throughout the several figures. 

The nature of this invention consists in the use of two cylinders set horizontally in a suitable framing 
and revolving in opposite directions, being driven by geering, which also propels the machine forward' 
as the brick is being made. 

One of these cylinders is fitted with moulds, working in which are followers, forming the bottom of 
the moulds, and operated by rollers moving in fixed grooved channels, and by cams producing the drop- 
motion. The second or pressing cylinder is provided with plates working and fitting into the moulds of 
the other cylinder, pressing the clay, which is fed from a hopper above and between the two cylin- 
ders, the clay being drawn into the several moulds by its own weight and the revolving motion of the 
C) imders, and the bricks deposited on the ground or surface prepared for them, in regular layers or line 
is the machine moves forwards ; a roller in front clears or prepares the ground or surface on which the 
oricks are to lay. The followers in the moulds are covered with cloth or similar material to prevent 
the clay or soft bricks from adhering to them — the machine being worked by hand or other power 



To enable others skilled in the art to make and use this invention, the inventor describes its construc- 
tion and operation as follows : 

A A is the frame of the machine ; B, the hopper through which the clay is fed ; C, a levelling-roller, 
serving to carry the machine, and to clear or prepare the yard for deposit of the bricks ; it works in a 
strap a, having a swivel-spindle 6, to admit of the machine being moved about in any direction. 

D D are travelling or propelling wheels fitted on the mould-cylinder shaft c and turning with it ; E' 
is the mould-cylinder keyed fast to the shaft c ; it is made of iron, or other suitable material, and has 
on its circumference or surface spaces ddd forming the moulds. The number of moulds is not limited 
to two rows, as shown in the drawing, but will be dependent upon the length of the cylinders as 
well as the diameter; each mould or space ddd being only of the length of the brick, so that the 
machine may, if required, be constructed to form three or more layers. 

E 2 E" E 2 are followers, or plungers, working in and forming the bottom of the mould ; thev are covered 
on their top with fine cloth ece, and are of length and breadth so as to fit loose in the moulds ddd in 
which they move, motion being given to them by rollers ///, which turn on spindles ggg running 
through the cylinder E' lengthways, passing through slots i i i at both ends ; the spindles ggg are con- 
nected to the followers E 2 E 2 E 2 by pieces h h h attached to them, through which the spindles g g g pass, 
the rollers///, as the cylinder E' is caused to revolve, moving in fixed grooved channels FF secured 
to the framing A A, the interior of one of which is seen in Fig. 3994-, being positioned with relation to 
the cylinder E' in the manner of an eccentric, one at either end, but differing from an eccentric in their 
being made of a scroll or irregular curve formation. The rollers/// travelling in the grooved channels 
F F, cause the followers E 2 E 2 E 2 to move in the moulds ddd, the followers at their bottom stroke leav- 
ing a space in the mould equal to or rather exceeding the thickness of a brick, and when forced out, 
working nearly to the outer edge of the moulds k k. 

Iu fig. 613, are represented cams attached to shafts 11, and so positioned and set as to form as 
many revolutions for one revolution of the cylinder E' as there are moulds in a single row, causing the 
cams k k, one at either end, to strike the rollers/// two together, that is, one at either end>and so on 
for all the rollers successively as they assume the position of/', Fig. 613, causing the formed bricks to 
be shaken from their moulds when arriving at a perpendicular position. The bottom of the mould- 
cylinder E' is situated rather more than the thickness of a brick from the ground or yard surface. 

G is the pressing cylinder revolving in the opposite direction to the cylinder E' ; it is keyed on the 
shaft m. nnn are pressing-plates fitted on the circumference or surface of the cyliuder G, correspond 


ing to the spaces or moulds d d d in the cylinder E', into which they fit or press the clay ; they are mads 
thicker at the edge first entering the mould than the finishing or after edge, as shown more particularly 
in Fig. 612. 

H is a handle for giving motion to the machine, (but the arrangement may be such that steam or 
other power may be applied.) I is a pinion turned by handle H ; it operates a wheel J, on the shaft 
of which is a pinion K working into a wheel L fitted fast to the side of the cylinder G ; the wheel L is 
in geer with a corresponding wheel M attached to the cylinder E' ; the wheel L also drives a pinion IS, 
on the shaft of which are wheels 0, one at either end, working into similar wheels P P that drive 
pinions Q Q fitted on the cam-shafts 1 I, which they operate. The relative proportions of these several 
wheels and pinions are such as not only to obtain additional power, but to operate the drop-motion 
formed by the cams k k at a proper time — that is, to strike the rollers when they assume the position 
of/', Fig. G13, so as to release the brick, and likewise to operate the propelling or travelling wheels, 
which are of a suitable relative diameter, so that the machine will move at a speed proportioned to the 
discharge of brick, causing the bricks made to be deposited regularly, side by side, in layers. 

The operation is as follows : clay being put into the hopper B, the handle H is made to turn, and by 
wheels and pinions 1J1CL and M the cylinders E' G are made to revolve in opposite directions, as 
shown by arrows in Fig. G12, drawing the clay, partly forced by its own weight, into the moulds 
ddd; the pressing plates re n «, entering the moulds at their thick edge first, press, and together with the 
moulds form the brick; the plates nnn leaving the moulds at their thin edge, obviates the tendency 
which the soft brick has of being pressed thinner at the side or edge, receiving the last or latest impres- 
sion. While the cylinders E' G are performing this operation, the machine, through means of the pro- 
pelling wheels D D, is moving forwards, and the several followers or plungers E 2 E 2 E 2 are being worked 
by means of the rollers/// travelling in the fixed grooved channels F F, which causes the followers or 
plungers E 2 E 2 E 2 to draw in for receiving the clay, and when the brick is made to be forced out, and so 
drive out the brick, which is further released from the mould t>y the action of the cams k k, driven by 
the geering N P P Q Q, the cams k k striking the rollers/// when arriving in the position of/ Fig. 
G13, and dropping or shaking the brick from the followers, which, being covered with fine cloth or 
other similar material, are not so liable to retain or cause the soft brick to adhere. The bricks are laid 
in the yard side by side and in perfect layers, in the manner shown in Fig 612, the number of 
layers being dependent upon the size of the machine or length of the cylinders E' G, which may 
have one, two, three, or more rows of moulds or pressing-plates. This machine, therefore, not only 
makes bricks rapidly, but of an equal thickness, sound and perfect ; and by being locomotive, can be 
moved about in any direction as convenience suggests, laying in the yard in regular order the bricks 
as made. 

BtUCK-HAIUXG MACHINE— "Whipple's Improvement, patented March 25, 1851. Fig. GH 
a diagram illustrating the pulverizing or crushing action of the machine. 

Fig. 615 is a side elevation of the machine. 
, Fig. 616 is a front or end elevation. 

Fig. 617 is a longitudinal section. 

Fig. 618 is a transverse section. 

The same letters of reference denote similar parts throughout each of the several figures. 

The nature of this machine consists in the use of a revolving 
screen working on a stationary axis set at a slight inclination . y ^^ 

from a horizontal position, and having attached to, or suspended i / *-' 

from it, lugs or crushers, which, by their weight, serve to pul- tt C\ 
verize the clay ; the stock or clay being fed in at one end of the v\. 
Bcreen, which by its revolving motion carries or drags the stock Vv -Y^o\ 

under the lugs or crushers, thereby breaking and pounding it ; V^"- — \0 ) 

the pulverized clay falling through the apertures of the screen, '-., ~— -__ji--^ — ' ya, 

and the waste or hard lumps and stones mixed up with the "-■.._ / L ..-*' 

stock being expelled at the back or lower end of the screen. ^ L" ~ifi &* 

A A are uprights having cross or tie pieces 6 6 6, which con- 
stitute the framing of the machine, or any simdar suitable form of framing may be adopted ; a a a 
are the bars forming the screen ; they may be placed at any required distance apart, and are bound, 
or secured, in a cylindrical form, by hoops B B, into notches in which the ends of the bars a a a may 
fit, or be otherwise attached. To the hoops BBare arms ddd, connected with naves F F, which 
form the rotary bearings of the screen ; the bars aaaa should be of such a shape in their cross sec- 
tion and so arranged as that any particles once entering the spaces, from within, between them, will 
readily pass off, that is, they should be broader on their interior than their exterior edges, thus 
making the outside width of the spaces greater than the inside, as is the case with many descriptions 
of fire-grates now in use ; and for which purpose bars of a triangular, or any appropriate shape, may 
be used, their narrowest or curved face or sides being set outside : or the screen may be made of a 
cylinder having slots or openings corresponding to spaces formed by the bars a a c t. C is the sta- 
tionary axis on which the naves F F of the screen rotate ; it rests on the lower cross-pieces 6 6, and is 
kept or prevented from turning by its back end s being made square, and an arm t being fitted into 
it, the other end of the arm t being fastened to one of the uprights A by a screw u, Fig. 615, or 
any other simple and well-known arrangement may be used for keeping the axis C stationary ; which 
is set, as Will be seen by reference to the drawings, at a slight inclination from the horizontal posi- 
tion, for the purpose of giving the screen a corresponding position, or a dip at its back end. D is a 
feed-hopper or trough, which also is stationary. To the axis C are keyed, or otherwise secured, arms 
h h 1 1 mm, seen more particularly in Figs. 617 and 618. n is a cross-bar connecting the arms h h 
is a bar connecting similar arms 11, and p a rod connecting the arms»n»rt. c c c c c are lugs oi 
crushers having their fulcrum, or working as a hinge-joint, on the rod 0, and at their other extremitv 



attached by cords or chains i i i i to the bar n, and resting on at their lower edge, or supported, bv 
the rod p.- either arrangement of the arms A A, cords or chains i i i i, or cross-bar p and arras »ik"s, 
may be used for supporting or holding the lugs from touching or rubbing the screen ; or both arrange- 
ments, as shown and described in combination, may be used. The lugs or crushers ccccc may be 
made of any material, size, shape, and weight, eeee are pickers arranged in a radial form round a 
small drum E, keyed to an axis r, working at either end in side-levers, or pieces F F. The pickers 
eeee are of nearly the same length as the bars aaaa of the screen, and are of proper thickness and 
width apart to drop into the spaces between the bars aaaa. The side-levers F F are hung on a rod 
x, forming a joint on which to work, and their other end connected by a bar G, which is held by a 
catch or hook g, Fig. 618, H H are pulleys, being driven by a handle I, attached to their shaft or 
axis. The pulleys H H serve to drive the screen by straps J J, which pass round them and the 
hoops B B. 

I will now proceed further to describe the operation. The stock, or rough clay, is fed by the hop- 
per D inio the screen formed of bars aaaa, entering under the lugs ccccc, and by the revolving 
motion of the screen in the direction shown by the arrows, Figs. 614, 616, and 618, the stock is carried 
under the lugs ccccc, which yield or give, working on their joint o, and so produce a pressure by 
their weight on the clay, which serves to clear the stock, the fine and workable portion being pul- 
verized and passing tlirough the spaces between the bars aaaa, and the waste or hard lumps and 
stones mixed up in the stock, being worked out of the back end of the screen, the inclination of which 
downwards, and the revolving motion of the screen serving to expel the same. The object of the rod 
p, or cords iiii, is to prevent the lugs from rubbing the screen, which would create unnecessary 
friction. The several lugs or crushers may be made of different sizes, shapes, or weights ; those at 
the mouth of the screen, if desirable, made so as to merely break the stock, and the after-crushers 



or lugs to pulverize the finer clay which is collected under the screen formed by the bars a a a a, and 
is thus tempered or prepared for making bricks. 

The pickers eeee may be thrown in or out of geer with the bars a a a a, by lowering or raising the 
side-levers FF, working as a hinge-joint on the rod x. By unfastening the hook g, Fig. 3999, the 
pickers eeee are thrown in geer, entering the spaces of the bars aaaa, which, as the screen rotates, 
drives or causes to rotate also the pickers eeee, which pick out or clear the screen of any soft clay or 
dirt which may clog the spaces between the bars aaaa. By the hook g the picker is thrown in or 
out of geer, and used only as required. 

BRICK PRESS. Patented by John Riddle, Covington, Ky., April, 1851. In order to the forma- 
tion by simple pressure, from untempered clay, of bricks possessing the requisite unity and coherency of 
structure, it is absolutely essential that the pressure should be uniform throughout their entire mass. 

This result has never, to our knowledge, been attained, except by the application of pistons on 
opposite sides of the brick ; but this mode, although (while the machinery remains in working order) 
adequate to the formation of a good article, is particularly ineligible, on account of its liability to 
clog and become deranged. The fact is, a brick-machine should have as few working joints as possi- 
ble, especially in those parts which are in immediate connection with the clay. 

Machines in which the bricks are formed either in the circumference of a large wheel or in a 
itraight bed of moulds, in connection with a wheel, by a simple rolling motion, have the requisite 
simplicity, but the pressure not being applied to all parts of the clay at once, the mass, while being 
pressed down at one part, rises up at other parts, which have passed the point of pressure, and 
cracks and becomes unequal in consistence ; and having once taken its set, no pressure afterwards is 
adequate to rectify the defect. These difficulties the inventor has entirely overcome by a working 
machine containing the following devices, to wit : 

Fig. 619 is a longitudinal section through the mould-wheel and its appurtenances. 

The moulds a are placed around the perimeter of a wheel b, and the pressed brick may be extruded 
by followers c, which may fall back against a solid shoulder in the wheel, as usual. 

The distinguishing features, however, of this arrangement exist in the peculiar construction of the 
feed-trough d, and its appendages ; the trough is made to gradually narrow downwards, until it 
comes closely in contact with the rim of the wheel, and is thence extended forward in the form of a 
Up or flange o, hugging closely the wheel, and made to bear hard up against it, so that the clay, after 
its introduction into the trough, is squeezed into a smaller and smaller compass, as it descends, and by 
this means is pressed forcibly into the mould, until, coming in contact with the lip, the entire mass 
receives its ultimate compression powerfully and equally applied in every part. 

BRIDGES. Bridges are constructed of various materials, arranged in varied forms. Bridges of 
atone or brick are arched ; of wrought iron, tubular and trussed ; of cast iron, plain girders ; of wood, 
trussed. Cast and wrought iron are often used together; wood and wrought iron, in trussed and suspen- 
sion bridges. 

The forms of arches are varied — the semicircular, the segmental, and the elliptic. The most common 
form in use in this country is the segmental (fig. 621), tie arc subtended being about 45°. Without 
going into the theory of the arch, requiring considerable mathematical knowledge, we proceed to give 
certain rules from the best authors, and examples of construction, to enable the mechanic to propor- 
tion the parts of a structure. 

That the voussoirs of an arch may resist crushing, they must have a certain depth proportioned to 
the pressure of the arch ; and as this increases from the curve towards the springing, the depth of the 
/oussoirs should likewise increase from the crown to the springing. Peronnet has given as a rulo for 



the depth at the crown the formula d = ,07 r + 1 foot, in which formula r is the greatest radius of 
curvature of the intrados. This formula is applicable to arches less than fifty feet radius ; but beyond 
this it gives greater dimensions than in ordinary practice. In order to facilitate investigations on the 
stability of arches of the more usual forms, M. Petit calculated a series of tables, of which we give tho 
abstract for circular arches, as the class occurring most frequently in practice. 

Fig. 621. 

To find the thickness of abutment necessary to support the thrust of the arch, multiply the co-efficient 
found in the table for the particular case by 3.S,. and the square root of the product multiplied by the 
radius, r, of the intrados, will give the extreme thickness of the abutment. 



Ratio of 

the Radii 


Fig. 620. 

Fig. 622. 

Fig. 621. 

■ — 11 

b — 5 h 


» - 6h 

> — 10 h 

s — 16 h 


IT *" " 

— — 3, 265 

"h ~ 5 



-h- 13 

— = 31.5 



0.2 ir 









































































Example. — What is the horizontal thrust, and -what the thickness of abutment necessary to support 
an arch of ten feet span and two feet rise ? 

r r 
A = ~2 


By Peronnet's formula, d = 0.07 

~l — -g , therefore s = 5h. 

r = 3.625 x 2 = 7.25 ft. 

7.23 + 1 = 1.50. 

R - 7.25 + 1.50 = 8.75 

R 8.75 
- = ™- = 1.20 

By the table against 1.20, under the column s = 5 h. we find 0.102 as the co-efficient of thrust, 150 
lbs. being taken as the average weight of a cubic foot of masonry, the absolute thrust per square foot 
of surface is 

0.102 x 150 x 7\25 : = SOI lbs. 

4.50 feet, thickness of abutment. 

V 0.1(12 x 3.8 x 7.25 

The formula gives the thickness of abutment, supposing the height infinite ; for low abutments, the 
thickness may be reduced, for common spans, about ten per cent. 

In the loading of a semicircular arch, especially, the tendency of a -weight applied at the crown, is to 
rise the haunches. This is to be counteracted by backing with masonry at these points called the 
spandrel backing. When the arch is to be covered with earth, care should be takeu in loading the 
arch. evenly at both sides. The same remark applies to the setting of the arch-stones on the wooden 
centres whilst in process of construction. 



The following table gives the dimensions of the arches of a selection of bridges of European con- 



Form of Arch. 





at spring. 

ft. in. 

ft. in. 

ft. in. 

ft. in. 

Manchester and Birmingham Railroad, 







London fend Brighton " 





1 6 

2 3 

" Blackball * ; 





4 1} 


Great "Western " 




24 3 


7 n 

Orleans and Tours " 



27 7 

2 71 


Stirling Bridge, .... 




13 6* 

3 6 

4 6 

Carlisle " 





3 9 

7 4 

Staines " 




9 3 

2 4 

5 6 

Iluteheson " . 




13 6 


4 6 

Jena " 



71 9 

10 9 


For smaller culverts of 15 to 30 feet span, the usual construction is to make the arch from 1 foot 6 
inches to 2 feet deep. Arches in stone are seldom turned less than 1 foot deep, whatever may he the 
span; brick arches for less than 10 feet span are generally 8 inches, and this depth is required by 
building acts. 

Details of oue of the arches and centreing of Waterloo Bridge 

Waterloo Bridge, London, by Rennie, is considered a masterpiece. It was commenced in 1S10, it is 
a level bridge, having nine arches, each 120 feet span, and 35 feet rise, and it is 42 feet 4 inches wide 
between the parapets. 

The bridge across the Seine, at Neuilly, built between the years 17G8 and 1780, by Peronett, is a 

Transverse section of Xeuilly Bridge. 



very celebrated structure ; it is also u level bridge, consisting of fire elliptic arclies, each of 128 feet 
span, and 32 feet rise. 

Iran bridges. — The most popular form of wrought iron bridges in England is the tubular, applied on a 
large scale, the travel being in the interior, as at the Conway and Menai Bridge. See Covway Tcec- 
lar Bridge. Or girders being constructed on this principle, over which the travel passes. See 
STRENGra of Materials. The first bridge of this latter class, in this country at least, was built in 
1846-7, on the Baltimore and Susquehanna Railroad, by James Milholland. Figs. 626, 627, 628, 
629, represent still another form of plate-iron bridge, as designed by Mr. Martin, the engineer, to carry 
the railway from the London and North-Western Railway to the East and West India Docks. It 
carries the railway over Randolph street, Camden Town. 

The peculiarity consists in constructing the bridge with two 
Fig. 626.— Side Yiew of Longitudinal side gi r tfers, each of a single web, of plates of iron, 71 feet long, 
tttt]-] 6 ft. 7+ inches high, and yy inches thick ; put together with plates 
=^M 5 inches wide, overlapping the vertical joints, and f-inch rivets 
placed 3 inches apart, and fixed to the top and bottom plates by 
angle-iron 3 inches wide, and f-inch rivets. The bottom plate is 
2 ft. 8 in. wide, made with y^-inch plates in lengths of 8 feet 
each, with plates overlapping the joints 6 in. wide. The outer 
flange is curved down 1 inch, to throw off the wet ; the top plate 
is 2 ft. 8 in. girt, made with y 5 B -mch plates, excepting the three 
middle plates, which are f-inch in thickness ; the top is curved 
down 5 inches, and put together with inch rivets. The girders 
J are stiffened by eight vertical plates on each side of the web, of 
s -inch iron, fixed by angle-iron 3 inches wide, and f-inch rivets placed 4 inches apart. There are 
also two similar stiffeners at each end, of f-inch iron. The top plate is further stiffened by stays of 

T-iron, 5i inches wide between each pair of stiffeners. 

Fi^. f>2-<. — Section through Girder, showing 
"the Stays to Stiffen the Top Piute. 
t.A_ _ 

The cress girders are 24 ft. 6 in. long and 1 ft. 4 in. high, made with 

Fig. 629.— Transverse Section 

one of the girders, showing the stiffeners. 
tavs to stiffen the top plate. 

'-inch plates in three lengths, 
and stiffened by angle-iron 
top and bottom, and on each 
side, 3^ inches wide, and fast- 
ened with f-inch rivets 4 
inches apart. The ends of 
these cross girders rest upon 
the two girders first described. 
Fig. 629 is a cross section 
of the bridge. Fig. 626 is a 
side view of part of one of 
^ f ""~ the longitudinal girders. Fig. 
627 is an enlarged section of 
628 is a section through the same girder, showing the 



Cast-iron Irhlgcs. — Bridges constructed of this material alone are usually of short span and simple 
girders. See Strength of Materials. Cast iron as a material is not considered as safe as wrought 
iron or wood ; from some flaw, from frost, or from sudden jars, it gives way without notice ; but as it is 
6tronger per square inch than wrought iron in resisting a crushing force, it has been applied in connection 
with wrought iron where the strain is of this description. Whipple's bridge, figs. 630, 1, 2, 3, 4, is a bridge 
<af this description. C80 


t"ig.680 represents the elevation, fig.631 the plan, and figs. 632, 3 and 4, the details of framing. This 
bridge consists of two iron trusses of 50 feet span, and 9 feet high. What would be called the nppe: 
chord consists of cast-iron pipe, 6 inches in diameter, and i inch thick, equal to 9 square inches — cast- 
iron uprights of + section, and 8 feet 4 inches apart from centre to centre, connect the upper chord on 
which the track rests, with the bottom or tie. This latter is of 1^ round iron, in loops, two of which, 
tide by side, constitute the tie between each pair of uprights. These loops pass over shoulders at the 
foot of the uprights, through which shoulders pass the diagonal 1^ inch wrought-iron rods, secured and 
adjustable by nuts. The dimensions of all parts of this bridge are proportioned to the strains they are 
to receive, and were calculated to withstand a rolling weight of 2,000 lbs. per running foot. 



The weight of one truss with its proportion of track is less than three tons, or 6,720 lbs., which is 
equivalent in its strain to 3,360 lbs. placed on the centre of each truss, to which add the weight at the 
centre to a load of 2,000 lbs. per foot rnn, viz., 25,000 lbs., and we have, as the weight on the centre 
of each truss, 28,360 lbs. 

The Rider iron bridge, of which fig. 635 is an isometrical view of the method of framing, is also a 
combination of wrought and cast-iron in the form of a truss, but it is deficient in strength. The upper 
chord is of cast-iron, in two parts, bolted together, and " breaking joint," and forming a T section of 
about 12 square inches. The lower chord is of wrought-iron, composed of two plates, each 4 inches 
deep, by i inch thick, placed side by side, with an interval of f inch between them to receive the diag- 
onal rods. These plates also " break joint," and at the joints have an additional plate of the same 
depth and thickness, and nearly two feet in length ; the whole secured together by four bolts, two on 

?ach side of the joints. The uprights or posts connecting the chords, and to which they are bolted, 
are of cast-iron, about 3 feet i inches apart, of an H section, and of 8 square inches in area. Through 
a hole in the centre of these pass the diagonal rods, two in each pannel, of wrought-iron 2 by f inches 
m the centre, and 2^ by 5£ inches at the ends ; these are also bolted to the top and bottom chord. 

Bollman's Bridge is still another combination of the same sort, but differs from the others in 
that there is no bottom chord necessary. The top chord and posts are of cast-iron, and the bottom 
of each post is supported by rods to either end of the upper chord. It may be considered a trussed 
cast-iron beam. The principles of the construction will be readily nnderstood from the description. 
The largest of these bridges is at Harper's Ferry, and they are used considerably on the line of the Balti- 
more and Ohio Rail Road. 

Fig. 636, is a perspective 
view of a part of Severson's Iron 
Bridge, near the abutment ; it 
is cambered about 1 in 80 or 
100 — the whole combinedform- 
ing a trussed girder. The sides 
or body of the truss, when 
made of cast-iron, will be com- 
posed of pieces, or voussoirs, 
corresponding in all parts with 
the arc of a circle, having a 
verse sine of 1 to a chord of 
80 or 100. The ends and joints 
between the voussoirs being 
radii, the main ties made of 
wire cables, and the lower and 
upper parts of the voussoirs, 
will form three concentric arcs. 

In fig. 637, at f is repre- 
sented a portion of the floor as 



Been from above ; A, the upper rail, or arc ; G G and H H the quarter braces ; E, end pieces. At B 
is half the bridge as seen from below ; D D, bottom of end pieces ; C C, main cables, or ties. The 
sway -braces and under side of girders between C C at B. 

Wooden Bridges. — The simplest form of bridges is of course composed of single beams 01 string- 
pieces spanning the opening, on which are laid the floor-planks. For the strength of such beams, see 
Strength of Materials. But as such constructions are only applicable to small spans, framed struc- 
tures become necessary. "We proceed therefore to investigate the general principles of trussing, applicable 
as well to iron as woodeu constructions. 

Fig. 1. Commencing with the simple truss, let a w, b to be two 

equal braces connected at the foot by the tie a b, and neglect- 
ing its own weight for the present, suppose the trass to sustain 
a weight W at the point w t Draw w c perpendicularly to the 
tie, and let it represent in magnitude the weight YV, that is to 
say, so many pounds as there are in YV ; let there be inches or 
half-inches or any convenient unit of measure in w c. Draw 
c d, c e, respectively parallel to w b and a w ; now by the com- 
\h position and resolution of forces, w e, measured by the same 
scale as w c, will represent the thrust in the direction of w b, 
caused by the weight w c or W; and w d likewise equals in direction and magnitude the strain or thrust 
in the direction of the brace a w. AYe suppose the framing to rest at the points a and b on immovable 
supports ; of course, half the weight, -J-W, will bear on each support, a and b; and the action at these 
points will be compounded of a vertical pressure equal to £W, and a horizontal strain or tension in tho 

a c 
direction a b, equivalent to £ W For drawing d e, parallel to a b, bisecting in f df represents the 

tension on the tie a b. For when three forces are in equilibrio about a point, if two of them 
are represented in direction and magnitude by the two sides of a triangle, the third side of this triangle 
must represent in direction and magnitude the third force. Now the point a is acted upon by 
three forces : an upward resistance equivalent to \ W, a pressure in the direction 10 a equal to d w, and 
the tension of the tie a b which will be the third side of the triangle of which the other two are d w and 
f wj, that is, (/ f j and in the similar triangles w d f xo a c, d w: fw: : aw: c w ; and df: f W. : a c : 
o w ; or the strain in the direction of a w bears the same relation to | W that a w bears to c w, and the 

a c 
tension on the tie Wars the same relation to I \< that a c bears to c u\ or tension = -i'W " — On the 


supposition that the braces are of different lengths, or the weight not immediately over the centre of the 
tie a b, we should still have the respective strains determined in the same manner. Thus w c represent- 
ing the weight w, sustained by the braces a w and b w. Completing the parallelogram on this as ft 
diagonal with the direction of the forces for the sides, and drawing d f parallel to the tie a b, we have 
as the result of this arrangement an inequality iu the action of the weight on the points a and b. w f 


represents the weight on the point a, and f c represents the weight 
on the point b ; and the side of the triangle w d f as in the first 
case, represents all the forces in operation on the point a — viz. : w f 
(the weight on a) wdiich bears the same relation to w c (or the 
whole weight) that c b bears to the whole tie a b. d w, the strain 
on the brace a w, and df the horizontal tension in the direction of 
the tie a b. 

To determine these strains in terms of the given dimensions, as 
in the first example, we have (taking for convenience of calculation 
a c as some multiple of a b, say ^) by similar triangles, d w : fw : 
a vi : c Wj and df : fw : : a c : c w; or the strain in the direction of 
. aw a c 

a w bears the same relation (o \ w that a w bears to c w : or d w = 3 "\V — and d f — 3 W — or 

H C 10 ^ "* c w 

the strain on any brace, ivill be as the length of the brace, divided by its height, and the tensions on the tie will 
he inversely as the height of the braces. 

The first expression, of the strain on the brace, is the cosecant of the angle of inclination of the 
brace ; and the tension on the tie is the cotangent of the same angle. 

We have shown the method to be pursued in calculating the strains on the respective braces or raft- 
ers, and ties or chords of a piece of framing, which may be either a truss for a roof, or for a bridge in 
its simplest form. 

Fig. 3, For short spans of either roof or bi"idge, say from thirty 

to forty feet, either of the two following forms may be 
used : The simplest is that shown in fig. , the truss 
resting on the points a a', and the roadway bearing on 
those points, and on cross bearers at the points c and d. 
This form of truss is, however, less economical than that 
of fig. , and less rigid. 

For the purpose of comparison, take a a, in figs. 
, divided into three equal parts at the points c and 
d, and suppose, with the same height b c to the two 
trusses, the points V b to be loaded with a weight, w. 
Now it is clear that the weight on the points a and a' is the same in each truss, but the tension on 



the tie is in the case of fig. 4, at a. 

2 a c , 1 a d 

-. w+ — — 

She 3 b' d 

but the tension on the tie of fin 

unless the abutments sustain the thrust ; for in the latter 
case in fig. 4, the braces b' e, b d cannot act directly on 

is, as before shown, 

Substituting in this expression the value of a d, which = 2 a c, and of b' d, which 
4 a c 

= 6 c, to hare the tension = w, which is \ greater than in the case of fig. 4, of course re- 

quiring \ more material ; which excess is not offsetted by the additional material required in the 
braces b rf, V c, of fig. 4, which is the preferable form, 4 

b b' 

3 a cuiiuoi auii uireuuy uu 

the abutments, as they may do in the case of fig. 3. 

Extending our investigation to longer spans, of say from 
40 to 80 feet, the number of bearing points for the distri- 
bution of the weight being increased in the proportion of 
the length, a comparison analogous to the preceding, will 
show the most economical arrangement for the timber of 
such a bridge. The independent brace for each point of 

support, throwing their weight directly on the abutments, is found not to be so economical as the intro- 
duction of a straining piece between the heads of the verticals. 

Taking the two trusses fig. 5 and 6, of the same span and rise, and divided into five eq^ial 
spaces, giving four points of support for the 5. 

load, which we will suppose to be distributed 
equally at the several points. 

In truss fig. 5, let a a' = 5 and a b, b c 
each = 1. Let w c = k and w b = £ k. 
The points a to w to w a may be considered 
as points in a circular arch, and in equilibrio 
under the weights w id w ic. 

The horizontal thrust on the tie, produced 
3 w. 
bv the weights w w &c. is = — — * 

For, as already shown, the action of ten- 
sion in this case will be represented by 

a b , a b 3 w 3 w 

w-f- w== = . 

£ h %k t h h 

In the case of the independent braces, fig. 6 being an equal space and rise, a a and h, and loaded 
with the same weight at the point, w w y &c. Each pair of braces will exert a certain thrust, and the 
tension on the tie will be expressed by the sum of the several thrusts produced by all the weights, or 

W 2 W n 3 70 4 w 4: w . . , . 

f T"+ f ~r + % ~r~ + 3 T~ == T~ 1S the tension on the tie, which is A- greater than m rig. 5, hence 

h h h h h 

this latter form of truss would require more timber than that of fig. 5, to bear the same load ; and 
attended with the inconvenience of the long braces, which would not bear the thrust communicated to 
them as advantageously, as the shorter pieces in fig. 5, but on the other hand the condition of equi- 
librium may be disregarded, as the weight may be removed from any of the braces without destroying 
the stability of the structure, whereas in fig. 6, to remove the weight from either of the points «?, 
would destroy the equilibrium, and the truss would yield at once ; to prevent this a system of bracing 
is introduced between the verticals (on the dotted lines), making the whole amount of timber about the 
same, probably, as in fig. 6, yet the truss with diagonal braces between the verticals, is preferable 
to that in which independent pairs of braces sustain the points at which the weight is applied, although 
the latter, as before remarked, is less liable to change of shape by a variable load ; the practical incon- 
veniences attending the construction of this form of truss, however, render it every way inferior to the 
other for long spans. 7. 

This form of diagonal bracing is the key to almost all our 
bridge constructions; we therefore extract from Haupt the 
principles of bracing and counter-bracing. 

If the truss, fig. 7, be loaded at c', the effect of the oblique 
force c' a upon the angle o, evidently, is to force it upwards, 
and this would be the diagonal of a parallelogram constructed upon a c and c c. 

This result is of the greatest practical importance, and the existence of a force acting upwards appears 
to have been overlooked by many practical builders, as in some very important structures no means 
have been used to guard against its effects. 

The consequence is, that in a straight as well as in an arched truss, a weight at one side produces a 
tendency to rise at the other side. 

The effect of this upward force is to compress the diagonals in 
the direction of the dotted lines, and extend them in the direction 
of the braces; but as the braces, from the manner in which 
they are usually connected with the frame, are not capable of 
opposing any force of extension, it follows that the only resist- 
ance is that which is due to the weight and inertia of a part 

of the structure. When the load is uniform this is sufficient, because the weight on one side is 
balanced by an equal weight upon the other, and every part is in equilibrium. But when the bridge 




is subjected to the action of a heavy weight, as a locomotive engine or a loaded car rapidly passing 
over it, and acting with impulsive energy upon every part at different instants, it is obvious that no 
adequate resistance is offered by a truss composed of only the three series of timbers already described. 
Yet we find that such a truss has been used for a large proportion of the bridges that have been erected, 
sometimes with, and sometimes without the addition of an arch, an appendage which, although it adds 
to the vertical strength, diminishes but little the effect of the force under consideration. No one who 
has had an opportunity of observing it, can have failed to notice the great vibration produced in such 
bridges by the passage of a loaded vehicle. In long bridges, the undulations produced by the passage 
of a car can be felt at the distance of several spans. 

The remedy for this defect is obvious ; it is only necessary to prevent the diagonal, in the direction 
of the dotted line, from shortening, or in the direction of the brace from lengthening, and the upward 
force will he effectually resisted. 

This requires either that counter-braces should be introduced in the direction of the dotted diagonals 
of the last figure, or that the braces themselves should be capable of acting as ties, or additional tie; 
placed in the direction of the braces. 

It follows, from the preceding exhibition of the effect of a variable load, that no bridge, either straight 
or arched, which is designed for the passage of vehicles, and particularly of railroad trains, should be 
constructed without counter-bracing or diagonal ties. It is only in aqueducts, when the load is always 
uniform, that they can with any propriety be omitted. 

Effects of counter-tracing. — The consideration cf the Action of counter-braces leads to some very 
singular but important results. 

Let the truss be loaded with a weight so as to produce some deflection, it has been shown that the 
diagonals in the direction of the braces will be compressed, and in the direction of the counter-braces 
extended. Suppose that the extension of the last named diagonals is sufficient to leave an appreciable 
interval between the end of the counter-brace and the joint against which it abuts, and that into this 
interval a key, or wedge of hard wood or iron, is tightly introduced ; it is evident that, upon the re- 
moval of the weight, the truss, by virtue of its elasticity, would tend to regain its original position; but 
this it cannot do, in consequence of the wedges at the ends of the counter-braces, which prevent the 
dotted diagonals from recovering their original length, and the truss is therefore forcibly held in the 
position in which the weight left it ; the reaction of the counter-braces producing the same effect that 
was produced by the weight, and continuing the same strain upon the ties and braces. 

The singular consequence necessarily results from this, that the passage of a load produces no addi- 
tional strain upon any of the timbers, but actually leaves some of them without any strain at all. 

9. To render the truth of this assertion more clear, we will confine our- 

■^ selves to the consideration of a single rectangle, and suppose that the 

/|\ effect of the flexure caused by an applied weight has been to extend the 

yS \ ^. diagonal A C by a length equal Aj?, and to compress the brace B D by 

yX * \ „_.__>£ an equal amount. 

yf The point p will evidently be drawn away from A, leaving the interval 
^. \ y/ A p. If a wedge be tightly fitted into this interval, without being forci- 

\ l/ bly driven, it evidently can have no action upon the frame so long as the 

^ weight continues ; but upon the removal of the weight it becomes forcibly 

compressed, in consequence of the effort of the truss, by virtue of its elas- 
ticity, to return to its former position. This effort is resisted by the reaction of the wedge, which causes 
a strain upon the counter-brace A C sufficient to counteract the elasticity of the truss ; and as no change 
of figure can take place, it follows that the brace B D cannot recover its original length, and therefore 
continues as much compressed as it was by the action of the weight. 

The effect of a weight equal to that first applied will be to relieve the counter-brace A C, without 
adding in the slightest degree to the strain upon B D. 

As regards the effects upon the chords, it is evident that the strains are only partial, and tend to 
counteract each other. The maximum strain in the centre is estimated by the force which would be 
required to hold the half truss in equilibrium if the other half be removed ; and this is dependent only 
on the weight and dimensions of the truss. In fact, if we examine the parallelogram A B C D, we 
rind that the effect of wedging the diagonals will be to produce strains acting in opposite directions at 
A and B, and destroying each other's effects; the strains produced by wedging any rectangle cannot 
therefore be continued to the next, and of course can have no influence upon the maximum forces at the 

As the vibration of a bridge is caused principally by the effort to recover its original figure after the 
compression produced by a passing load, it follows that if this effort is resisted, the vibration must be 
greatly diminished, or almost entirely destroyed. 

This accounts for the surprising stiffness which is found to result from a well-arranged system of 

Inclination of braces. — 1. The braces must not be so long as to yield by lateral flexure. 

2. The chords being unsupported in the intervals between the ties, these intervals must be limited 
by the condition that no injurious flexure shall be produced by the passage of a load. On the other 
hand, as the ties approach each other, the angle of the brace increases; and when the intervals become 
small, the number of ties and braces is greatly increased, and with them the weight of the structure. 

The true limit of the intervals can be readily determined when the size of the chords and the max- 
imum load are known; for it should evidently be such that when the load is at the middle, the flexure 
should not exceed a given amount. 

Figs. 038 and 039 represent bridges of which the braces, posts and chords are entirely of wood, but 
in more common forms wrought iron is used for such parts as are subjected to tension. 







The most popular form of bridge in use in this country is Howe's truss, similar in form to fig. 8, the 
bottom and top chords being composed of timber in several thicknesses, the main braces being double, 
and the counter-braces single, the tension rod or post being of iron. The braces abut on an angula* 
block either of wood or iron, and the tension rods pass through the centre of the block. 

In Pratt's bridge the posts are wood, and suspension rods supply the place of braces. 

The peculiarity of McCallum's bridge, is in the arrangement through which the arched upper chord 
by means of the arch-braces bearing on the abutment, together with the connter-brace tension-rodf 
acting on the lower chord, conduce to a uniformity of action highly advantageous to the durability of 
the bridge. 

Suspension Bridges. — Various opinions have been entertained as to the form best adapted for the ob- 
jects of a suspension bridge. These objects are, — 1st, the obtaining a roadway across a river in a po- 
sition where it is necessary to allow the passage of vessels beneath it, and where it is not possible to 
form piers or abutments sufficiently close together to allow of an ordinary arch being constructed. 2d, 
the judicious arrangement of the suspending chains, rods, and roadway bearers, to effect the greatest 
firmness and rigidity with the least expenditure of material 

The different forms maybe arranged under the following heads. First, — those in which the plank- 
ing of the roadway, (except a small portion near the abutments,) rests solely on the main suspending 
chains, as in Chinese bridges generally, and some in South America. 

Second, — those in which the roadway side beams, carrying the planking, railing, &c, are only con- 
nected with the main suspending chains by vertical rods, as in the Menai Bridge and numerous others. 

Third, — those in which the roadway platform is entirely supported by ropes, chhins, or wires proceed- 
ing obliquely from the top of the abutments, as in some bridges of rope, canes, or bamboos in Asia, and 
light wire bridges in Europe. 

Fourth, — those in which the roadway platform is partly supported by ropes, chains, or wires proceed- 
ing obliquely from the top of the abutments, partly by rods descending obliquely from the main chains, 
and partly by the main suspending chains themselves ; which last diminishing in weight as they ap- 
proach the middle of the span, are linked to the central portion of the roadway by short rods, which 
being nearly in continuation of the upper parts of the main chains, would, if strong enough, support 
that part of the roadway, and complete the curve, rendering the central link of the chain nearly unne- 

In all suspension bridges, chains are carried from the top of the abutments to the rear, and called 
back chains. There is one of these to each of the bridge chains, whether they carry the rods on each 
side, as in those of the second class, or go directly to the platform, as in the third and fourth classes. 
These back chains are connected with links secured on the top of cast iron saddles on the abutments at 
one end, and firmly bolted to cast iron auchor plates or blocks of masonry in the solid ground or rock 
at the other. 

In the annexed plate is shown an elevation of the Niagara Falls Suspension Bridge, constructed by 
John Itoebling, C. E, of the United States. This bridge has a span of 821 feet 4 inches, from centre to 
centre of towers. Its form is a slightly curved hollow beam or box, of a depth of 18 feet; width of 
bottom 21 feet, and of top 25 feet. The lower floor is used for common travel, while the upper is ap- 
propriated to railway business and sidewalks. The two floors are connected by two trusses of a simple 
construction, so arranged that its resisting action operates both ways, up as well as down. The suspen- 
ders are 5 fijet apart. The beams of the upper and lower floor are connected by posts arranged in 
pairs, leaving a space between for the admission of the truss rods, which extend each way to the fourth 
pair of posts at an angle of 45°. These rods therefore cross each other and form a diamond work. 
They are 1 inch diameter, their screw ends 1^ inch. 

There are 4 cables of 10 inches diameter, each composed of 3,640 wires of small No. 9 gauge, 60 wires 
forming one square inch of solid section, making the solid section of each cable 60.40 square inches, 
wrapping not included. Each of the four large cables is composed of seven smaller ones, which are 
called strands. Each strand contains 520 wires; one of these forms the centre, the six others being 
placed around it ; the ends of the strands are passed around and confined in cast-iron shoes, which also 
receive the wrought iron pin that forms a connection with the anchor chains. During the wrapping 
process the whole mass of wire was saturated with oil and paint, which, together with the wrapper, will 
protect the cables effectually against all oxidation. There are 64 diagonal stays, of If inch diameter 
rope, above the floors, equally distributed among the four cables. They are fastened to the suspenders 
by small wrappings, so as to form staight Hues; they are not continued over the towers to the anchor- 
« age, but are secured to the saddles, and allowed to move with them. To the under side of the lower 
floor 5Q stays are attached, which are anchored in the rocks below, and occupy positions calculated to 
insure against horizontal as well as vertical motions. The anchorage of the back chains was formed 
by sinking 8 shafts into the solid limestone rock that here composes the uppermost stratum of the 
cliffs. Three of the pits on the New York side are sunk to a depth of 25 feet. The fourth one, 
south-east, was sunk only 18 feet, on account of the great influx of water, and difficulty of baling. 
The surface of the rock on the Canada side being 10 feet higher than on the New York side, the depth 
of the shafts was increased that much, and the height of the towers above reduced in proportion. Each 
shaft has a cross section of 3 x 7 feet, enlarged at the bottom to a chamber of 8 feet square. The 
anchor chains are composed of 9 links, all of which are 7 feet long, except the uppermost or last one, 
which is 10 feet. The first or lowest link is composed of 7 bars, 7 x 14 inches, and is secured to a 
cast-iron anchor plate by a pin of S\ inches diameter ground upon its seat. The next link is com- 
posed of 6 bars of the same size, and 2 half bars on the outside. The aggregate section of each is 69 
superficial inches ; from the fourth link up, the link on the chain curves and the section is gradually 
jicreased to 93 superficial inches. 

On the top of each column a cast-iron plate was laid down, well bedded i'J cement, 8 feet square 




and 2A inches thick, and strengthened by three parallel flanges for the reception of two independent sad- 
dles. "Each saddle rests on ten cast-iron rollers, 5 inches in diameter and 251 inches long, placed close 
tot-ether. The ordinary pressure upon each tower being about 500 tons, makes each roller bear 25 
tons. These rollers admit of a slight movement of the saddles, whenever the equilibrium between 
the land and the suspension cables is disturbed, either by changes of temperature or by passing trains. 
The success of this extraordinary bridge may now be considered as established. The trains of the 
New York Central, and of the Great Western Rail Road in Canada, have been crossing regularly since 
its completion, averaging over thirty trips per day. _ 

BRONZING. Improvements in the Brassing and Bronzing the surfaces of steel, iron, dr., by Charles 
de la Salzede of Paris. This invention consists in coating cast-iron, steel, lead, zinc, and tin, with 

la _, brass or bronze, by means of a galvanic battery. The solution to be used 

consists of 5,000 parts, by weight, of distilled water, 610 parts snbear- 
bonate of potass, 25 parts chloride of copper, 48 parts of sulphate of zinc. 
305 parts of nitrate of ammonia, and 12 parts of cyanide of potassium 
The cyanide of potassium is dissolved by itself, in about 120 parts of dis 
tilled water taken from the above quantity. The other salts above men 
tioned (except the nitrate of ammonia) are then added to the remainder ol 
the water, and the mixture is heated to from 144° to 172° Fahrenheit, 
when they are entirely dissolved the nitrate of ammonia is added, and the 
solution allowed to stand 24 hours ; the solution of the cyanide of potas- 
sium is then added, and the whole allowed to stand till it is quite clear ; the 
clear solution is then to be drawn off with a siphon, and put in the decom- 
posing trough. The subject to be covered with brass is then to be attach- 
to the zinc pole of a battery ; and to the other pole of the battery a large 
plate of brass is to be attached, which must be also immersed in the solu- 
tion. The battery must, the patentee says, be a powerful one : he advises 
to use Bunsen's or Grove's. When it is intended to bronze, instead of the 
48 parts of sulphate of zinc, 25 parts of chloride of tin must be used ; the 
other ingredients are to remain the same. Another solution recommended 
by the patentee, consists of 5,000 parts of distilled water, 15 parts of chlo- 
ride of copper, 35 parts of sulphate of zinc, 500 parts of subcarbonate of 
potass, and 50 parts of cyanide of potassium for brassing ; and for bronz- 
ing, 1 2 parts of chloride of tin, instead of the 35 parts of sulphate of zinc ; 
this solution, the patentee says, must be used at a temperature of from 25° 
to 36° cent. The proportions, the patentee says, may be varied within 
certain limits. 

BUCKET-WHEELS. See Water-wheels. 

BUFFING APPARATUS. A contrivance for receiving the shock of a 
collision between railway carriages, consisting of powerful springs and 

The buffing apparatus first used upon the Liverpool and Manchester 
Railway consisted of elliptic iron springs, or bows, of several thicknesses, 
placed transversely across the middle of the frame-work of the carriage 
which received the shock of whatever blows or jerks the buffer-heads might 
receive, by the aid of rods communicating with the same. Mr. Bergin, of 
Dublin, contrived an improved buffing apparatus for the carriages of the 
Dublin and Kingstown Railway. 

It is supported upon the axles of the wheels, and is totally unconnected 
with the frame of the carriage, whereby it does not partake of the rise and 
fall of the latter, according to the weight acting upon the vertical springs ; 
and two strong iron rods are passed through the whole length of the car- 
riage, which rest upon small rollers, to which the buffer-heads are attached, 
spiral springs being wound round them, which receive the effect of all 
shocks, by the help of collars formed upon the rods, and the introduction 
of stops to the springs. 

On American Rail Road Cars the coupling and buffing apparatuses are 
usually combined in one. The cars are attached to each other by a single 
link of chain, inserted in the jaws of the buffer-heads, and retained by iron 
pins passing down through the buffer-heads and links. This arrangement is 
sometimes made self-acting, to obviate the necessity of standing between 
the cars to insert the links and pins. The buffing bars are of iron, with 
convex heads at their points of junction, and bear against springs, attached 

^i_ to the bottom of the car, the draught acting from the centre. 

— ,_ , — i — W To obviate the oscillations of cars and wagons, which produce strains 

^^" ^ ■■ylHl °n the axles and other parts, injury to the road-way, and deterioration 

6ection of Berlin's Buffing t0 f re 'S nt ! tne connection between the parts of a train should resemble 

Apparatus. as much as possible the jointing of the vertebra? in an animal's back-bone 

by which means the lateral action of a car would be neutralized by the support of the neighboring 

ones. The methods at present adopted for coupling and drawing trains are open to great improvement. 

The mode of coupling cars in freight trains without spring-buffers or draw-bars is liable to lead to 

accidents from the play which must necessarily be allowed between the cars to admit of their going 

round curves, since each time the speed is slackened, the cars close up, and at a fresh start the chains 


are exposed to a sudden jerk. The best mode of connection is the coupling screw, by means of -which 
the ca:s are drawn together so that the buffers are pressed into close contact, and their springs a little 
compressed. In this manner the train is formed into one complete column, and the change of speed to 
which it is subject does not produce the partial collision mentioned. 

BUHL-WORK, or BOOL-WORK. The terms appear to be corrupted from Boule, the name of the 
original inventor, and now refer to any two materials of contrasted colors inlaid with the saw. In 
France this kind of inlaid work is called marqucterie. It consists in representing flowers, animals, 
landscapes, and other objects, in their proper tints, by inlaying. It also includes geometrical patterns 
composed of angular pieces laid down in succession, as in ordinary veneering, and is chiefly used in or- 
namenting cabinet work. In buhl-work the patterns generally consist of continuous lines, as in the 
honey-suckle ornament. Two pieces of veneer of equal size, such as ebony and holly, are scraped 
evenly on both sides, and glued together, with a piece of paper between. Another piece of paper is 
also glued outside one of the veneers, and on this the pattern is drawn. A small hole is then made 
for the introduction of the saw, a spot being chosen where the puncture will not be noticed. 

The saws used in buhl-work are of peculiar construction, and of different sizes. The frames are of 
wood or metal ; three pieces of wood halved and glued together constitute the three sides of a rectangle ; 
two pieces are then glued upon each side, each at an angle of 45' across the comers ; the whole when 
thoroughly dry is then cut round to the desired curve. Screws for giving tension to the blade are 
commonly added, but seldom used, as the frame is only sprung together at the moment of fixing the 
saw, and by its reaction stiffens the blade. A handle is attached to the saw frame at the bottom. In 
the piercing saw of metal the height from the blade to the frame is usually eight inches, and in the 
ordinary buhl-saw of wood from twelve to twenty inches, to avoid the angles of large work. 

The buhl-cutter sits astride a horse or long narrow stool ; the work held in the left hand, is placed 
in a vice at one extremity of the horse, having a flexible jaw under the control of the foot ; the saw, 
which has been previously inserted into the hole in the veneers, and fixed in its frame, is grasped in the 
right hand, with the fore-finger extended, to support and guide the frame. " The several lines of the 
work are now fullowed by short, quick strokes of the saw, the blade of which is always horizontal ; but 
the frame and work are rapidly twisted abo-^t at all angles, to place the saw in the direction of the sev- 
eral lines. Considerable art is required in designing and sawing these ornaments, so that the saw may 
continue to ramble uninterruptedly through the pattern, whilst the position of the work is as constantly 
shifted about in the vice, with that which appears to be a strange and perplexing restlessness. When 
the sawing is completed, the several parts are laid flat on a table, aud any removed pieces are replaced. 
The entire work is then pressed down with the hand, the holly is stripped off in one layer with a paint- 
er's palette knife, which splits the paper, and the layer of holly is laid on the table with the paper down- 
wards, or without being inverted. The honey-suckle is now pushed out of the ebony with the end of 
the scriber, and any minute pieces are picked out with the moistened finger ; these are all laid aside ; 
the cavity thus produced in the ebony is now entirely filled up with the honey-suckle of holly, and a 
piece of paper smeared with thick glue, is then rubbed on the two to retain them in contact. They are 
immediately turned over, and the toothings or fine dnst of the ebony are rubbed in to fill up the inter- 
stices ; a little thick glue is then applied, and rubbed in, first with the finger, and then with the pane of 
the hammer, after wdiich the work is laid aside to dry." When dry it is scraped at the bottom, and is 
then ready to be glued on the box or furniture to be ornamented, as in ordinary veneering; it is after- 
wards scraped and polished. An ebony honey-suckle may be inserted in a ground of holly in the same 
manner; and these form the counter or counterpart-bulil, in which the pattern is the same, but the color 

Three thicknesses of wood may be glued together, as rosewood, mahogany, and satin-wood, which, 
when cut through, split asunder, and recombined would produce three pieces of buhl-work, the grounds 
of which would be of either kind with the honey-suckle and centre of the two other colors respective- 
ly. These are called " works in three woods," and constitute the general limit of the thicknesses. 
Buhl-works of brass and wood are also sometimes made by stamping instead of sawing. 

BULLETS. Manufacture of by Rolling. At the Arsenal, at Woolwich in England, they now manu- 
facture leaden bullets by drawing and compression. These bullets have the advantage of being without 
blows or air cavities, and are rolled out of round bars of lead, which are passed between rolls formed 
like the roulettes used for ornamental work on the lathe. The rolls are constructed with hemispherical 
cavities, each one of which forms one-half of the ball, whilst the corresponding cavity forms the other 
half; the bullets are then finished by removing the extra metal, and being rolled together in a barrel. 

The bars of lead from which the balls are compressed are cast in moulds, 36 inches in length by 75 
in diameter. These bars are then brought to the machinery, and are first passed through a roller, which 
condenses the lead, and prepares it for the second operation, that of compressing it into shape or form 
for the die. Thirdly comes the die, which by its regular movement forward is brought into contact with 
the masses of lead prepared, and as the die recedes, a boy moves up the bar fur its next movement, 
and so on ; following it up with other bars of lead arranged at his right band, so that the die in its for- 
ward movement always finds its work prepared, and leaves the balls formed in a belt of lead. The 
fourth and last operation is that of cutting the balls out of the belt, which is done by a punch, exactly 
the diameter of the bullet, and which is brought over it and worked by a boy with his foot. The ad- 
vantage of the compressed over the cast bullet is its perfect solidity ; whereas the cast has a flaw, 
more or less, in every bullet. The belted or rifle ball should, therefore, always be made by com- 
pression. The following is a description of a machine invented by Wm. H. Ward, of Auburn, N. Y., 
for manufacturing bullets from lead wire. The wire is coiled upon rests at the top of the machine, and 
suspended by means of arches, from which the lead is fed downwards into the machine, where it is 
measured and cut off as required for each bullet, after which it is forced forward into dies, and formed 
into the desired shape by compression. This machine is capable of making musket, rifle, and pistcl, 



elongated, hollow, and conical expansion bullets ; also round or shell balls, all at the same rime. Each 
corner being double with two sets of dies and punches, gives eight bullets to one revolution of the ma- 
chine. The machine may be worked up to twenty-five turns in a minute, which is equal to 200 bullets 
per minute, or 12,000 per hour. 

BULLET-WOOD. See Woods, varieties of. 

BUNG-CUTTING MACHINE. We here present two views of a machine invented by Messrs 
Dowdy & Sweet, No. 35 Cross-street, of this city. Fig. is a side elevation, and fig. a view 

of the cutter-stock and cutters. A is a stout table. H is a strong upright-post in the middle of the 
table. To this post the cutter-shaft C is secured by proper bearings D D, to allow it to revolve. F is 
a screw which passes through a bearing G, into an opening in the head of N. J is an elevating bed or 
rest for the plank that is to be cut into bungs. It is fixed on a treadle J, by a foot-spring K; 
when pressed upon towards L, the bung-bed is elevated through an opening in the middle of the 







A ° 

table, and as the foot presses K, so is the plank fed up to the cutter till the bung is cut, when the fool 
being released, the bung is driven out by a spiral spring, which will be better understood by Fig. 621. 

A is the cutter-stock. It is of a cylindrical form, with an opening through the e „j 

centre, and a thread a short distance at the upper end to screw in the shaft C. 
In the centre of the cutter-stock is a spindle with a spiral spring on it, represented 
by D. The spring does not reach to the ends of the spindle. By an open- 
ing in C, the shaft is allowed to pass into it, when the plank is fed into the 
cutters ; but when the bung is cut, this spiral spring in the centre of the cutter- 
stock recoils as the feed-table is lowered, and throws out the cut bung. This is 
the object and use of the interior spiral spring and spindle. G F H are the cut- 
ters. Each is a distinct piece, and each performs a different office. They are all 
set on to the cutter-stock, which is turned on the outside, leaving them to sit 
around it like a ring, where they are covered with a snug collar B, and a screw 
E E, for each cutter, secures them to the cutter-stock. The inside of the cutters 
is like a cup, and they are arranged almost like screws of different pitch. F has 
two little spurs on it ; one on the inner side, and the other on the outer. These 
cut the cresses of ihe groove in the plank for the bung, when H follows after and 
scoops it out, cutting on the outside of the bung. Both of these cut straight with- 
out any taper. G is the taper cutter. It is graduated in the edge to the bottom 
of the cutter-stock ; therefore it gradually planes the taper of the bung, after the 
other two cutters have done the rough work. This makes the work easy on the 
machine, which cuts out about 20 bungs per minute, hand fed, with great ease. 
On the bottom of the stock, in the inside of the cutters, there is a small knife 
that rims off the edge of the bung. This machine has been in operation suc- 
cessfully for some time. 



BURXETTIZIXG, the process for preventing the rapid decay of timber, by the use of chloride of 
_inc. The liability of nearly all kinds of timber in common use to rapid decay, when exposed to alter- 
nate wet and dry, or when placed in damp and badly ventilated situations, has led to various devices for 
the purpose of increasing its durability under such circumstances. 

In 1838, a patent was granted in England to Sir William Burnett, for a process for preventing decay 
in certain vegetable and animal substances by the use of chloride of zinc. This process, called Burnet - 
tizing, has been extensively used in England as a preventive of the decay of timber ; and it has been 
more extensively used in this country for the same purpose than any other process. No patent was 
taken out for the United States. It was first introduced at Lowell, Massachusetts, where, in 1850, the 
Proprietors of the Locks and Canals on Merrimac River, at the joint expense of the manufacturing 
companies, erected the necessary apparatus for carrying on the process. Although it is not in all cases a 
preventive of decay, the advantages are more than sufficient to justify its application to most kinds of 
timber in common use, when placed in situations favorable to rapid decay. It has also a distinct effect 
in rendering wood less liable to warp and crack when placed in dry situations. 

The apparatus at Lowell consists of a cast-iron cylinder, in which the timber to be prepared is 
placed : this cylinder is sixty feet long, and five feet diameter inside, with one head movable ; the iron 
generally an inch thick. A pair of rails, about two feet gauge, are laid in the bottom of the cylinder, 
and also on the same line and level, about seventy-five feet outside the cylinder ; a low track, about 
sixty feet long, runs on these rails. When it is required to charge the cylinder with timber, this truck 
is drawn out, loaded, the load chained down to prevent its floating, and the truck then drawn into the 

A little below the level of the cylinder, and parallel to it, is placed a wooden cistern, to hold the so- 
lution while the cylinder is being loaded and unloaded, and at times when the apparatus is not in use ; 
this cistern is about fifty feet long, seven feet wide, and four feet deep, and was originally constructed 
for Kyanizing by immersion. The air-pump is twelve inches in diameter, and three feet stroke. The 
force-pump four inches in diameter, and two feet stroke. The pumps are worked by a small steam 
engine of about fifteen horse-power, which also works the windlass by which the truck is drawn in and 
out of the cylinder. The boiler of the engine is also used in winter to supply steam to thaw frozen 
timber ; this is done by admitting steam into the cylinder, charged with the frozen timber, for several 
hours before the vacuum is obtained. The steam eugiue and boiler are both much larger than necessary 
for these purposes. 

The process is as follows : — 

" The truck being outside the cylinder, is unloaded and reloaded with about seven 
thousand feet, board measure, of lumber, usually of various kinds and dimensions ; 
from one to two hours is usually thus occupied, depending upon the dimensions and 
variety of sizes, — average, say _________ 

"Drawing in the truck and packing cylinder head ------ 

*' Exhausting the air, and maintaining a vacuum of twenty-seven or twenty-eight 
inches of mercury ------------ 

" Changing pumps, and at the same time filling the cistern by atmospheric pressure 
from the cistern, with a solution of one hundred parts of water and one and a half parts 
of dry chloride of zinc by weight, and getting xvp the pressure in the cylinder to one 
hundred and thirty pounds to the square inch above the atmosphere - 

" The pressure of one hundred and thirty pounds to the square inch above the at- 
mosphere is maintained ----------- 

" Draining off the surplus solution by gravitation from the cylinder to the cistern - 

*' Unpacking head and drawing out track ------- 

" Time occupied in preparing one batch," 

Time occupied. 















By allowing the solution to drain off during the night, two hatches per day are easily done. 

"Whenever it is required to prepare large quantities of timber, uniform iu kiud and dimension, such 
as railroad sleepers, an improvement iu the above process would be, to maintain the pressure until a 
certain quantity of the solution was taken up ; but with the great variety in kind and dimension usually 
prepared at the same time, this is impracticable ; as the lumber of small thickness gets more than its 
due proportion, and the pressure is kept up so long in order that the larger sizes may be sufficiently sat- 
urated. The chloride of zinc is received from the manufacturers in the form of concentrated solution 
containing about 55 per cent, of the dry chloride. The amount taken up by the wood varies very much, 
depending upon the kind, dimensions, and dryness of the wood ; as the process is conducted at Lowell, 
it varies from about ten pounds to forty pounds of the concentrated solution to a thousand feet board 
measure, or from two to eight ounces to a cubic foot. 

BUSH. A piece of metal, usually made of hard brass, and fitted into a cai 

plumber-block, in which the journal turns ; they are also sometimes termed 
pillows, and the blocks, pillow-blocks. The guide of a sliding-rod is also term- 
ed a iusfi. Thus, in Fig. 622, A is the piston-rod, B B the bush. 

BUSHES, metal for lininq. See Details or Engines. 

BUTTON MACHINERY. Buttons may be divided into two general 
classes, — those with shanks, or loops of metal, for the purpose of attaching 
them to garments, and those without shanks ; and each class is manu- 
factured from a great variety of materials, and by a variety of methods. Of 
Duttons with shanks the greater number are composed of metal, although glass and mother-of-pearl 
are also employed for the purpose. Aletal buttons are formed in two different ways, the blanks or bases 
of the buttons being either cast in a mould, or stamped out of a sheet of metal ; the former method ia 
generally employed for making white metal-buttons, and the latter for plated and gilt buttons. To cast 



buttons, a great number of impressions of the pattern of the button are taken in sand, and in the een 
tre of each impression is inserted a shank, the ends of -which project a little above the surface of fha 
sand, and fused metal is poured over the mould. When cooL the buttons are taken from the moulds, 
and after being cleansed from sand by brushing, are placed in lathes, the edges are turned, the face and 
back smoothed; and the projecting part of the shank also turned. The buttons are then polished by 
rubbing the faces upon a board spread with rotten-stone of different degrees of fineness, and afterwards by 
being held against a revolving board covered with leather, upon which is spread a very fine powder of 
the same material ; finally, they are arranged on a sieve or grating of wire, and immersed in a boiling 
solution of granulated tin and cream of tartar, by which nutans their surfaces become covered with a 
lliin laver or wash of the metal, which improves their whiteness without injuring their polish. The 
blanks "of plated buttons are cut by a fly-press out of copperplate, coated on one side with silver. 
They are then annealed in a furnace, and afterwards stamped by the descent of a weight, as in a pile- 
driving machine, the die being fixed in the lower surface of the weight. The soldering of the shank is 
performed on each button separately, by the flame of a lamp and a blowpipe : the edges of plain but- 
tons are next filed smooth in a lathe, and the buttons are afterwards boiled in a solution of cream oi 
tartar and silver ; they are then placed in a lathe, and the backs brushed, and afterwards burnished 
with blood-stone. The metal used for gilt buttons is an alloy of copper and zinc. This metal is rolled 
out into sheets, and the blanks stamped out, which are then planished, if intended for plain buttons ; but 
if for figured buttons, the impression is now given. The shanks are next attached, which is effected as 
follows : each blank is furnished with a pair of small spring tweezers, which hold the shank down upon 
it on the proper place, and a small quantity of solder and resin is applied to each. They are then ex- 
posed upon an iron plate to a heat sufficient to melt the solder, by which the shank becomes fixed to 
the button ; and whilst still warm they are plunged into nitric acid, to remove the oxide formed on the 
surface by the heat employed in soldering the shanks. They are then placed in a Lathe, the edges rounded, 
and the surfaces rough-burnished, wliich renders them ready for gilding. Five grains of gold are fixed by 
act of parliament, in England, as the least quantity to be employed in gilding a gross of buttons of one 
inch in diameter. An amalgam is formed of gold and mercury, and the buttons are placed in an earth- 
en vessel along with the amalgam, together with as much aquafortis as will moisten the whole, and the 
mixture is stirred with a brush until the buttons are completely whitened. To dissipate the quicksilver 
the buttons are shaken in an iron pan, placed over a fire, until the quicksilver begins to melt, when they 
are thrown into a felt cap, and stirred with a brush, to spread the amalgam equally over their surfaces ; 
after which, they are returned to the pan, and the mercury volatilized completely by the increased heat, 
le iving the gold evenly spread in a thin film over the surface of the buttons ; they are then burnished 
in a lathe, which completes the operation. The better sort of buttons undergo the gdding process 
twice or thrice, and are distinguished accordingly as " double" or " treble gilt." Glass buttons are 
formed of glass compressed, while in the fluid state, in moulds, in wliich the shank is inserted, and when 
the glass becomes cold, the shank is firmly retained in its place. In mother-of-pearl buttons the meth- 
od of inserting the shank is extremely ingenious : a hole is drilled at the back, and undercut — that is, 
larger at the bottom than at top ; and the shank being driven in by a steady stroke, its extremity ex- 
pands ; on striking against the bottom of the hole, it becomes firmly riveted into the button, forming a 
kind of dove-tail joint. 

Buttons without shanks are of two kinds ; the first are simply disks of horn, bone, wood, or other 
material, with four holes drilled through the face, for the purpose of sewing them to the garment. 
Horn buttons of this description are made from cow-hoofs by pressing them into heated moulds. The 
hoofs having been boiled in water until they are soft, are first cut into plates of the requisite thickness, 
and after into squares of the size of the diameter of the button, and afterwards reduced to an octag- 
onal form by cutting off the corners. They are then dyed black by immersing them in a caldron of 
logwood and copperas mixed. A quantity of moulds somewhat resembling bullet-moulds, and each 
furnished with a number of steel dies, are then heated a little above the point of boiling water, and 
one of the octagonal pieces of horn is placed between each pair of dies, and the mould being shut is 
compressed in a small screw-press, and in a few minutes, the horn becoming softened by the heat, 
receives the impression of the die, after which the edges are clipped off by shears, and then rounded 
in a lathe. The holes in buttons of this description are chilled by means of a lathe, represented in the 
annexed engraving. Four spindles, of which two only, a a, can be seen, are supported in bearings at i, 

and by the centre points c c are made to revolve with great velocity by means of two bands d d passing 
over pulleys e e fixed upon each of the spindles, each band driving two spindles, and receiving motion 
from a wheel worked by a treadle. At the end of each of the spindles a, is a hook uniting them to 
four other spindles// by similar hooks at one end, the other end of the spindles passing through four 
small holes in the plate g, and the projecting points being formed into small drills. The button is placed 
m a concave rest /(, and pushed forward against the drills by a piece of wood. The standard r/ can be 


exchanged for another with holes more or less apart, and the rest h can be set at any height to sui' 
different-sized buttons. As the spindle-holes in the plate g are nearer together than the holes in the 
standard b, the spindles ff converge ; the hooks in the spindles are therefore necessary to form a uni- 
versal joint. The second' description of buttons without shanks consists of thin disks of wood or bone, 
called moulds, covered with silk, cloth, or other similar materials. The bone for the moulds is made 
from refuse chips of bone sawed into thin flakes, and brought into a circular form by two operations, 
illustrated by the accompanying engraving. On one end of the spindle a, which revolves in bearing? 

at b b, is screwed a tool c, and on the other are two collars dd, between which a forked level e embraces 
the shaft, the fulcrum of which is at/. The spindle a is put in rapid motion by a band g passing over 
the pulley h, and over a band-wheel worked by a treadle ; and the workman, holding the material i for 
the mould in his right hand, against a piece of wood k firmly held down in the iron standard I by two 
screws, by means of the lever held in his left hand, he advances the tool c against the material ;' of 
the mould ; the central pin of the tool drills a hole through the centre of the intended mould, whilst 
the other two points describe a deep circle cutting half through the thickness of the material, and the 
flat surface is cut smooth by the intermediate parts of the tool. The tool is then drawn back a little 
by the lever e, and the material shifted to bring a fresh portion of the surface opposite the tool, and 
when as many moulds as the plate of the material will afford, are thus half cut through, the other side 
is presented to the tool, and the central point of it being inserted in the hole made in the first part ol 
the operation, the other two teeth cut another deep circle exactly opposite the former one through the 
remaining substance of the material, and the mould is left sticking on the tool ; by drawing back the 
lever e the tool recedes, and the mould, meeting a fixed iron plate, is pushed off the tool, and falls into 
a small box m. 

Covered buttons having come into very general use, various improvements have been introduced 
in the manufacture of them, and patents for this purpose 
have been granted to various parties. The following is Mr. 
Sanders' method of making covered buttons : a piece of the 
material with which the mould is to be covered is cut of a 
circular shape, somewhat larger than the intended button ; upon 
this is placed a disk of card of the exact size of the button, and 
next a disk of paper coated with an adhesive composition, which 
will become soft and sticky by heat ; and upon these is laid a 
button-mould e, having four holes, through which threads or 
strings have been passed to form the flexible shank. These 
circular disks being put together, are then laid over a cylindrical 
hole in a metal block a ; this hole being exactly the size of the 
intended button, and the covering of the button being larger 
than the hole, when the disks are pushed down into the hole, the material of the covering will wrinkle 
up on the edges round the other disks. The tube 6 6 is then introduced into the cylindrical hole, and 
its lower edge being bevelled inwards, will, as it is pressed down, gather the plaits of the cloth on the 
edge of the button ; towards the centre is a metal ring or collar c, having teeth round its edge, some- 
what like a crown-saw, wliich is now passed down the tube b, and driven with considerable force by the 
punch d, and the block a having been previously heated, the adhesive matter will be softened, and cause 
the several disks to stick together, which, when taken out and become cold, will be very firm and retain 
its shape. 

Button shanks are made by hand from brass or iron wire, bent and cut in the following manner: 
The wire is lapped spirally rounfl a piece of steel bar. The steel is turned round by screwing it into 
the end of the spindle of a lathe, and the wire by this means lapped close round it till it is covered. The 
coil of wire thus formed is slipped off, and a wire fork or staple with parallel legs put into it. It is now 
laid upon an anvil, and by a punch the coil of wire is struck down between the two prongs of the 
fork, so as to form a figure 8, a little open in the middle. The punch has an edge which marks the 
middle of the 8, and the coil being cut open by a pair of shears along this mark, divides each turn of 
the coil into two perfect button shanks or eyes. 

Harding's Improvements. — These improvements in the manufacture of buttons and other dress fasten- 
ings, consist in the arrangement and construction of the parts whereby they are secured to the dress, for 
which two separate methods are given. According to the first method, the button is formed with a 
thank of a single wire, which after projecting a sufficient length from the hack of the button to pass 





b i 

s « 



through the garment, is turned at right angles, and coiled in the form of a spiral in a plane parallel to 
that of the button. The spiral consists simply of about two turns, and terminates abruptly. On se- 
curing this button to the garment, the end of the spiral is inserted through a small eyelet hole just suf- 
ficient to admit the entrance of the wire ; the button is then turned round, and the wire screwed through 
the hole in the garment until the whole of the spiral passes underneath the vertical shank then occupy- 
ing the hole, and the button is thereby secured, iu which position it is held until the button is drawn 
from the garment and turned in the contrary direction. This mode of securing dress fastenings is also 
applicable to other fastenings, such as clasps, &c., the mode of attachment of which is precisely similar, 
the spiral and shank being attached to the article in any suitable manner to occupy the proper position 
for the purpose. 

The second fastening is for a similar purpose, but for securing the ordinary description of shank but- 
ton, or other dress fastening having a suitable shank. It merely consists of a piece of doubled wire, so 
as to form an eye ; the continuations of the wire form a hook and clasp pin after being threaded through 
the shank of the button ; the pin portion is spnmg into the hook part whereby the wire is securely re- 
tained in its position. The button shank is first introduced through an eyelet hole, and the fastening 
placed at the back as described. 

BUTTON-WOOD. See Woods, varieties of. 

BUTTRESS. A piece of strong wall that stands on the outside of another wall to support it, or ap- 
plied as an ornament. 

CABLE. See Chain Cable. 

CALCINATION. The chemical process of subjecting metallic bodies to heat with access of air, 
whereby they are converted into a pulverulent matter, somewhat like lime in appearance. The term 
calcined, is, however, now applied to any substance which has been exposed to a roasting heat. 

CALCULATING MACHINES. Machines of this kind are designed to produce arithmetical and 
other tables, which shall be rigorously correct. In navigation and the higher branches of astronomy the 
use of such tables is very great, and being constructed by human heads and hands, they all contain er- 
rors of greater or less magnitude. The principle upon which these machines are constructed may be 
described as follows. In the manner in which quantities are combined in the common system of nume- 
ration, the value of each figure is ten times greater than it would be if it occupied a position one place 
to the right. Thus, in the number 1829, although 9 is greater than 2, yet the 2 in this position repre- 
sents a larger sum than the 9, because it occupies a place to the left of the 9. The quantities really 
expressed by the figures 1829 are 1000, 800, 20, 9 ; but in practice we omit the cyphers, and place 
the significant figures side by side, preserving their proper position from the right hand. If a wheel 
he constructed on whose axis is a pinion with leaves or teeth ; if these teeth work into another set of 
teeth or cogs on the periphery of another wheel, and if the teeth on the latter wheel are just ten 
times as numerous as those on the pinion, this system being made to revolve, the pinioned wheel 
will revolve just ten times as fast as the other. This produces a kind of analogy between the decimal 
notation and the working of the wheels, for it takes 10 units to make up one figure or unit in the sec- 
ond place in common numeration, and it requires 10 revolutions of the pinioned wheel to impart 1 
revolution to the larger wheel. This is the fundamental principle in calculating machines. In such 
machines there are a number of dial-faces, each marked with figures from 1 to 10 ; these dial-faces are 
fixed upon wheels, the teeth of which work into the pinions of other wheels, on which are similarly 
divided faces or discs, so that while one face indicates units, another indicates tens, a third hundreds, 
and so on. The* wheels and dial-faces may he differently arranged in different machines, but the prin- 
ciple is the same in all. 

A calculating machine, called the Difference Engine, was constructed by M. Babbage for the English 
government at an expense of £20,000, to be used in preparing logarithmical and trigonometrical tables. 
A valuable feature introduced into this machine is the power of printing the tables as fast as it calcu • 
lates them. Another machine, called the Analytical Engine, was invented by the same gentleman, of 
greater power than the first. This contains a hundred variables, or numbers, susceptible of changing, 
and each of these numbers may consist of twenty-five figures. The distinctive characteristic of this 
machine, is the introduction into it of the principle which Jacquard devised for regulating, by means 
of punched cards, the complicated patterns of brocaded stuff. See Abaccs. 

CALEMBERG. See Woods, varieties of. 

CALENDER. A machine used in the manufacture of cotton and linen goods. Calendering is the 
finishing process by which the goods are passed between cylinders or rollers, and made of a level uni- 
form surface. The machine consists of a number of rollers contained in a massive frame-work ; the 
rollers are connected with a long lever loaded with weights at the further extremity, by which or by 
means of screws almost any amount of force may be applied, and the surface texture of the cloth va- 
ried at pleasure. With considerable pressure between smooth rollers, a soft silky lustre is given by 
equal flattening of the threads. By passing two folds at the same time between the rollers, the threads 
of one make an impression on the other, and give a wiry appearance with hollows between the threads. 
The rollers are made of cast-iron, wood, paper, or calico, according to the uses for which they are de- 
signed. The iron rollers are sometimes made hollow for the purpose of admitting either a hot roller of 
iron, or steam when hot calendering is required. The other cylinders were formerly made of wood, but 
it was liable to many defects. The advantage of the paper roller consists in its being devoid of anj 
tendency to split, crack, or warp, especially when exposed to a considerable heat from the contact and 
pressure of the hot iron rollers. The paper takes a fine polish, and being of an elastic nature, presses 
into every pore of the cloth, and smooths 'ts surface more effectually than any wooden cylinder, how- 
ever truly turned, could possijly do. 

In a five rollered machine, the cloth coming from behind, above the uppermost or 1st cylinder, passei 



between the 1st and 2d ; proceeding behind the 2d, it again comes to the front between the 2d and 3d ; 
between the 3d and 4th it is once more carried behind, and lastly brought in front between the 4th and 
5th, where it is received and smoothly folded. At this time the cloth should be folded loosely, so that 
no mark may appear until it is finally folded in the precise length and form into which the piece is to be 
made up, which varies with the different kinds of goods, or the particular market for which the goods 
are designed. When the pieces have received the proper fold, they are pressed in a hydraulic press pre- 
vious to being packed. 

From the great weight of calendering machines it is necessary that they should be fixed on the base- 
ment floor. After the cloth has received its final gloss from these machines, it is taken to the cloth- 
room to be measured preparatory to being folded and packed for sale or transportation. 

CALENDER WITH FIVE "ROLLERS, Designed and Constructed by Messrs. A. More and Son, 
Glasgow. Fig. 644, an end view; Fig. 643, a side elevation; the same letters of reference denote the 
&ame parts in each view. 

A A A, three cylinders or rollers made of paper, the construction of which will be noticed afterwards. 

B B, two cast-iron cylinders, made hollow to allow of the introduction of hot bolts of iron within them ; 
or of steam, when it is required or preferred. 

Scale.— l-4th inch = 1 foot. 

Scale.— l-5th inch = 1 foot 

C C, the two side-frames or cheeks, into which are fitted the several brass bushes for the cylinders to 
turn upon. 

D D, top guides, into wliich the cross-head G-, and elevating screws H H, work. 

E E, top-pressure levers, connected by a strong rod of iron with the under-pressure lever F. This 



system of levers is connected with the cross-head G, by two strong links of iron. The elevating screws 
H H pass through the cross-head, and rest upon a strong cast-iron block, into which is fitted the brass 
bush of the top paper roller. By means of the screws, the cross-head and levers can be raised or 
depressed as required, and when the calender is working warm and requires to be stopped, the elevating 
screws are screwed up for the purpose of lifting the paper rollers off the hot cylinders, to prevent their 
being injured by the heat. 

The construction of the paper rollers or cylinders is as follows : Upon each end of an arbor of malle- 
able iron, of sufficient strength to withstand the necessary pressure without yielding, is fastened a 
strong plate of cast-iron, of the same diameter as the roller to be made ; the plate is secured in its 
proper place by a ring of iron, cut in two, and let into a groove or check turned in the arbor. When 
the roller is finished, the annular pieces are kept in their groove by a hot hoop put upon the outside 
of them, and allowed to cooL A plate is fitted on the other end, of exactly the same size, and in the 
same manner. 

In building the rollers, one of the plates is taken off the arbor, but the other is allowed to remain in 
its place. The paper sheets of which the rollers are to be made, have each a circular hole cut in the 
centre of it, of exactly the same diameter as the arbor. The sheets are then put upon the arbor, and 
pressed hard against the fixed plate. When the arbor is filled witli paper, it is put into a strong 
hydraulic-press, and pressed together, — always adding more paper to make up the deficiency caused by 
the compression, until the mass will press it no harder. The half rings are then put in their place, to 
prevent the plate from being pressed back by the elasticity of the paper. The roller is now to be dried 
sufficiently in a stove, the heat of which causes the paper to contract so as to be quite loose. The roller 
is then again taken to the press, and the unfixed plate being removed, more paper is added, and the 
whole again compressed, until the roller is hard enough for the purpose to which it is to be applied. It 
is next turned truly in the lathe till it acquires a very smooth surface. 

The wood-cut. Fig. 647, shows the manner in which the calender is geered to make it a glazing 
calender. In this cut, a marks the top cylinder of the calender, upon which is keyed a spur-w T heel 6 ; 
and c is the under cylinder, upon which is also keyed a spur-wheel d. The intermediate or carrier- 
wheel e e, when drawn into geer, reduces the speed of the under cylinder c, one-fourth. Now, the cylindeT 
o, being the one that gives motion to all the rollers, and revolving always at the same speed, the cloth 

in its passage through all the rollers below the cylinder a, is carried through at a speed one-fourth less 
than if it passed only below the cylinder a ; consequently, when it comes into contact with a, it is 
rubbed, and thereby glazed, in consequence of the cylinder a moving one-fourth quicker than the cloth, 
as above stated. 

The wood-cut, Fig. 648, shows the manner in which the rollers are lifted clear of each other when the 
machine is stopped. In this, ee are two rods of iron, attached to the block or seat of the top roller ; 
bfg, three bridges of malleable iron, capable of sliding upon the rods ee ; but held fast upon the rods 
when once they are adjusted to their proper places by pinching screws. The bridge b is placed half an 
inch clear of the bearing of the cylinder a, when all the rollers are resting upon each other ; the bridge / 
is placed one inch below the bearing of the paper roller h ; and the bridge g is placed one inch and a 
half below the bearing of the cylinder c. When the pressure screws of the calender are lifted, the 
blocks of the top roller being attached to them, the rods e e are lifted also, and along with them ihe 
different rollers as the bridges successively come into contact with their respective bearings. 

The manner of passing the cloth through the calender varies very much, according to the amount of 
finish required upon it. The various methods are accomplished by different arrangements of the 
geeriug, so that a calender calculated to do all the different kinds of finishing becomes a very compli- 
cated maclune, on account of the quantity of geering required. For common finishing, the method of 
passing the cloth through the calender is as follows : — The cloth is passed alternately over and under a 
series of rails placed in front of the machine, so as to remove any creases that may be in it, and is then 
introduced between the lower roller A and cylinder B ; returns between the lower cylinder B and the 
centre roller A ; passes again between the central A and the upper B, and again returns between the 
top pair A, B, where it is wound off on a small roller, (hid in the drawings by the framing of the 
machine,) pressing against the surface of the top roller A. When this small roller is filled with cloth it 
is removed, and its place supplied by another, to be in succession filled as the motion of the machine 



Water-Mangle with two copper, and three wooden rollers; designed and constructed by Messrs. A. 
More and Son. — Tliis machine, Figs. 645 and G46, differs nothing in principle, and little in general 
construction, from the five-rollered calender above described, except in this — that it is intended 
for wet goods. It is drawn to a scale slightly less, but the views given and the lettering of the parte 
correspond to those of the preceding figures. 

AAA, the three wooden rollers, and B B, the two copper rollers of the mangle. These last consist 
of a copper cover upon a cast-iron body, through which passes a wrought-iron arbor, differing from those 
of the wooden rollers in being round, whereas these are square between the bearings. The smaller ot 
the two copper rollers, namely, the third in order, is in this arrangement the driver, the mangle being 
driven like the calender, by a system of reversing geer not shown in the drawings. 

The pressure in the mangle is brought on by a system of levers, which differ slightly from that 
described. In this, indeed, there are strictly two distinct pressures : that brought on the axis of the 
middle roller by the lever E, which is connected by a link with the weighted lever F ; and that 
transmitted through the whole system of rollers by the single-weighted lever D. The weight of this 
last is regulated by means of a set-screw, which turns in a nut in the jaws of the lever D, and bears 
upon the set-block which rests upon the arbor of the top roller. This pressure is thus transmitted 
downwards from the top roller throughout the whole set, and at the middle roller B is added to the 
pressure obtained by the lever E. By this arrangement, the pressure between the three under rollers 
is greater by the pressure of E, than it is between the upper pair ; but, for very high pressure the lever 
D may be locked by set-pins and the set-screws turned down by the hand-wheel G-, until the requisite 
degree of pressure is obtained. 

The manner of passing the cloth through this machine is the same as that already described in the 
calender, with this single exception, that before the cloth enters between the lowest roller A, and the 
small cylinder B, jets of water from a pipe, perforated with small holes, extending the whole width of 
the machine, are allowed to play upon the cloth, so as to impart to it sufficient moisture for causing it to 
receive the requisite degree of smoothness preparatory to the starching process, and at the same time 
allow the cylinder B to free it from any impurities that may be remaining in it, by forcing them back 
with the expressed water. 

CALENDER, Description. A, two cast-iron frames. BCD, three cylinders. EFG, three cog 
wheels. H I, two force-screws. K L, two fly-wheels with handles. 

The cylinder B, which is in cast-iron, and hollow, is heated by another iron cylinder heated red hot 
The material of the cylinder C is pasteboard, its axle is of wrought-iron. These three cylinders must 
De perfectly round and parallel. 

The whe'el F forms the communication between E and G, which rest upon the cylinders B and D 
The relation of F to the. circumference of the cylinders is such, that when the machine is set to work 



these cylinders slide, causing friction, and thus give a gloss to the cloth. The friction is variable ao 
cording to the nature of the tissue. 

In order to set the machine in motion, the fly-wheels K and L being turned in order to press the 
screws Hand I against the pillows of the first cylinder B, the cloth is placed between the rollers in the 
direction indicated by the arrows. 

CALICO PRINTING. The art of producing a colored patttern on cloth by the application of col- 
oring substances. The processes employed are applicable to linen, silk, worsted, or mixed fabrics, 
although they are usually referred to cotton cloth or calico. 

The invention of cylinder or roller printing, is attributed to two persons, one a Scotchman named Bell, 
the other named Oberkampf, a calico printer at Jouy in France. 

The cylinders upon which the pattern is engraved, one cylinder for each color, are mounted on a 
strong frame-work, so that each cylinder revolves against two othe'r cylinders, one of which is covered 
with woollen cloth, and dips into a trough containing coloring matter properly thickened, so that, as it 
revolves, it takes up a coating of color and distributes it over the engraved roller, which transfers the 
pattern to the cloth. The cloth to be printed passes over a large iron drum covered with several folds 
of woollen cloth, so as to form a somewhat elastic printing surface : an endless web of blanketing is 
made to pass round this drum, which serves as a sort of guide, and defence, and printing surface to the 
calico which is being printed. The superfluous color is removed from the engraved roller by a sharp- 
edged knife or plate usually of steel or gun-meta], called the color doctor, so arranged, that the color 
scraped off shall fall back into the trough; another plate of steel removes the fibres which the roller 
acquires from the calico. 

As many as eight colors may be printed at once by one machine, but very great nicety of arrange- 
ment is required to bring all these rollers to bear upon the cloth, so as to print at the exact spots re- 
quired for forming a complicated pattern. 

The printing cylinders are of copper, and vary in length from 30 to i0 inches, according to the width 
of the calico ; the diameter varies from i to 12 inches. Each cylinder is bored through the axis, and 
accurately turned from a solid piece of metal. To engrave a copper cylinder by hand with the multi- 
tude of minute figures which exist in many patterns, would be a very laborious and expensive opera- 
tion, and the invention of Mr. Jacob Perkins in America, for transferring engravings from one surface 
to another by means of steel roller dies, has long been applied to calico printing with perfect success. 
The pattern is first drawn upon a scale of about 3 inches square, so that this size of figure being repeated 
a number of times will cover the printing cylinder. This pattern is next engraved in intaglio upon a 
roller of softened steel, about 1 inch in diameter and 3 inches long, so that it will exactly occupy its 
surface. This small roller which is called the die, is next hardened by heating it to redness in an iron 
case containing pounded bone-ash, aud then plunging it into cold water, its surface being protected by a 
chalk paste. This hardened roller is put into a rotatory press, and made to transfer its design to a sim- 
ilar roller in a soft state called the mill; the design which was sunk in the die now appears in relief on 
the mill. The mill in its turn is hardened, and being put into a rotatory press, engraves or indents 
upon the large copper cylinder, the whole of the intended pattern. 


It is often necessary to apply some substances to the cloth which shall act as a bond of union betweei 
it and the coloring matter. These substances are usually metallic salts called mordants, -which have an 
affinity for the tissue of the cloth as well as for the coloring matter when in a state of solution, and 
form with the latter an insoluble compound. The usual mordants are alum, and several salts of alu- 
mina, peroxide of iron, peroxide of tin, protoxide of tin, and oxide of chrome. Mordants are useful 
for all vegetable and animal coloring matters which are soluble in water, but have not a strong affinity 
for tissues. The action of the mordant withdraws them from solution, and forms with them upon the 
cloth certain compounds which are insoluble in water. 

To prevent the mordant or the coloring matter from spreading beyond the proper limits of the de- 
sign, thickeners are used to bring it to the required consistency ; the most useful are wheat starch and 
flour, hut many other materials are used for this purpose. The colors, with the proper thickeners, are 
prepared in vessels furnished with steam jackets, for raising the contents to the required temperature. 

There are eight different styles of calico printing, each requiring different methods of manipulation, 
and peculiar processes 

1. The madder style, (so called from its heing chiefly practised with madder,) to which the best 
chintzes belong, in which the mordants are applied to the white cloth with many precautions, and the 
colors are afterwards hronght up in the dye-bath. These constitute permanent prints. 2. The padding 
style, in which the whole surface of the calico is imbued with a mordant, upon which afterwards dif- 
ferent colored figures may be raised, by the topical application of other mordants joined to the action 
of the dye-bath. 3. The resist style, where the white cloth is impressed with figures in resist paste, 
and is afterwards subjected first to a cold dye, as the indigo vat, and then to a hot dye-bath, with the 
effect of producing white or colored spots upon hlue ground, 4. The discharge style, in which thickened 
acidulous matter, either pure or mixed with mordants, is imprinted in certain points upon the cloth, 
which is afterwards padded with a dark colored mordant, and then dyed, with the effect of showing 
bright figures on a dark ground. 5. China blues; a style resembling hlue stone ware, practised with 
indigo only. 6. The decoloring style, by the topical application of chlorine or chromic acid to dyed goods. 
This is sometimes called a discharge. 7. Printing by steam, a style in which a mixture of dye extracts 
and mordants is topically applied to calico, while the chemical reaction which fixes the colors to the fibre 
is produced by steam. 8. Spirit colors ; produced by a mixture of dye extracts, and a solution of tin. 
These colors are brilliant hut fugitive. 

The processes actually' required for finishing a piece of cloth in the madder style, as for example, in 
producing a red stripe upon a white ground, are numerous. The bleached cloth is submitted to nine- 
teen operations, as follows : — 1. Printing on mordant of red liquor, (a preparation of alumina,) thick- 
ened with flour and dyeing ; 2. Ageing for three days ; 3. Dunging ; 4. Wincing in cold water ; 5. 
Washing at the dash wheel ; 6. Wincing in dung-suhstitute and size ; 7. Wincing in cold water; 8. Dye- 
ing in madder; 9. Wincing in cold water; 10. Washing at the dash wheel ; 11. Wincing in soap water 
containing a salt of tin ; 12. Washing at the dash wheel ; 13. Wincing in soap water ; 14. Wincing in a 
solution of bleaching powder; 15. Washing at the dash wheel; 16. Drying by the hydro-extractor; 17. 
Folding ; 18. Starching; 19. Drying hy steam. 

CALICO : Machine for printing in four colors. In this machine the pressure is normal, in all ths 
engraved rollers, by the means of the levers P. These rollers are turned by a belt communicating with 
the prime mover. The regulators are adjusted by screws, to -which are attached hands, indicating, upon 
dials, the space to be run by the rollers in order to reach the regulators : this is known without stopping 
the works. 

The engraved rollers can be brought up to the pressing cylinder, or withdrawn from it, without 
changing the places of the color-vessels or of the scrapers, for all the different pieces fixed against the 
pillows on the turning pieces of the engraved rollers, move with these last. Finally, there is an appa- 
ratus placed behind the under cloth, the intermediate cloth, and the stuff to be engraved, by which the 
workman governs these three pieces at will. 

The engraved rollers are sometimes made of copper, sometimes of brass, or of copper and tin. The 
first are to be preferred, being less apt to be injured; with such a cylinder 30,000 pieces can be 
printed with the most delicate patterns. 

The brass cylinders will be injured in proportion to the acidity of the printing-mixture, the zinc being 
attacked. Those in whose composition tin is introduced are more hard, but also more difficult to en- 
grave. Some of these cylinders are hollow, others are massive : either may be used. 

The diameter of the cylinders varies from 023 to 0'82 feet, according to the option of the manufac- 
turer, and also to the dimensions of the pattern. 

The dimensions of the pressing-rollers make no difference in the impression : the lesser ones should, on 
certain considerations, be preferred, for the engraved rollers always yield under the pressure of the first, 
so that it becomes necessary to give a curve to the pressing-roller equal to that of the engraved ; and 
as the pressure it exercises is inversely to the augmentation of its diameter, it becomes necessary to 
increase the weight on the subterraneous levers, thus giving still more chance to the engraved cylinders 
to bend. 

M. Huguenin thinks that a pressing-roller having only a diameter of 0-856 feet, for machines printing 
only one color, and that of those printing several colors, the smallest possible must be used. In some 
manufactures these rollers are wrapped with a band of a tissue, the warp of which is flax, and the weft 
of worsted, having the property of not lengthening under pressure ; at the centre of the roller, this 
envelope is 0062 feet thick, at the extremities 0-032 feet. The most modern improvement in this respect 
is the introduction of a tissue of cotton and caoutchouc. 

The furnishing rollers have their circumference enveloped in a woollen cloth ; their speed is inferior 
to that of the engraved cylinders ; their diameter is generally about 0-328 feet 

The vessels in which the rollers dip are made of copper or wood. It is necessary to keep them sup 



plied with a constant quantity of printing material, for the rollers would soon only skim over the sur- 
face of the fluid and leave but a feeble impression ; to this end a reservoir pours a continual supply. A 
partition is placed in a position which enables it to clear the roller of the froth with which its surface 
may be covered. 

A A, frame-work. 

BBBB, pressing; cylinder. 

CCCC, engraved cylinder. 

DDDD, scrapers. 

EEEE, vessels containing the color- 
ing matter: they are raised and 
lowered at pleasure, by the screws 

GGGG, endless screw, guiding the 

BHHH, pinions and wheels which 
turn all the machinery. 

I, a shaft communicating with the 
moving power. 

KKKK, wheels adapted to the fe- 
male screws LLLL, which put 
the levers in communication with 
the pillows of the rollers. 

M, a wheel communicating with the 
driving power, whose office is to 
press the rollers ; it also moves the 
wheel N, and the endless screws 
OOOO, which a-e engaged with 
the wheels KKKK. 

PPPP, levers which are loaded with 
weights in proportion with the 
pressure required: they are situ- 
ated beneath the floor. 

Q, the cylinder round which the cloth 
to be printed is rolled. 

R, the cylinder round which the in- 
termediate cloth is wound. 

S, a weight which keeps the clolh 
stretched on the cylinders QU. 

T, a roller used to give an inclination 
to the cloth when printed, and reg 
ulate the speed. 



CALORIC ENGINE, Ericsson's Patent. The invention consists in producing motive power by tht 
application of caloric to atmospheric air or other permanent gases or fluids susceptible of considerable 
expansion by the increase of temperature. The mode of applying the caloric being such, that aftet 
having caused the expansion or dilatation -which produces the motive power, the caloric is transferred tc 
certain metallic substances, and again retransferred from these substances to the acting medium at cer- 
tain intervals, or at each successive stroke of the motive engine, the principal supply of caloric being 
thereby rendered independent of combustion or consumption of fuel; accordingly, whilst in the steam- 
engine the caloric is constantly wasted by being passed into the condenser, or by being carried off into 
the atmosphere, in the improved engine, the caloric is employed over and over again, thereby dispens- 
ing with the employment of combustibles, excepting for the purposes of restoring the heat lost by the 
expansion of the acting medium and that lost by radiation, also for the purpose of making good the 
small deficiency unavoidable in the transfer of the caloric. 

We now proceed to describe the structure of the improved engine for producing motive power, refer- 
ence being had to fig 652, A and B are two cylinders of unequal diameter, accurately bored and provided 

Fig. 652 

with pistons a and &, the latter having air-tight metallic packing rings inserted at their circumferences. 
A b the supply cylinder, and B the working cylinder, a' piston-rod attached to the piston a working 
through a stuffing-box in the cover of the supply cylinder. C is a cylinder with a spherical bottom at- 
tached to the working cylinder at c c ; this vessel is called the expansion heater. D D, rods or braces 
connecting together the supply piston a, and the working piston b. E is a self-acting valve opening in- 
wards to the supply cylinder; F, a similar valve, opening outwards from said cylinder, and contained 
within the valve-box^ G is a cylindrical vessel, which is called the receiver, connected to the valve- 
box^ by means of the pipe g. H, a cylindrical vessel with an inverted spherical bottom, is called the 
heater. J, a conical valve supported by the valve stem J, and working in the valve-chamber J', which 
chamber also forms a communication between the expansion heater C and heater H, by means of the 
passage 7i. K is another conical valve, supported by the hollow valve-stem k, and contained within the 
valve chamber k\ L and M, two vessels of cubical form filled to their utmost capacity, excepting small 
spaces at top and bottom, with disks of wire net, or straight wires closely packed, or with other small 
metallic substances, or mineral substances, such as asbestos, so arranged as to have minute channels 
running up and down. These vessels, L and M, with their contents, are termed regenerators. I /, m »*, 
pipes forming a direct communication between the receiver G, and the heater H, through the regenera- 
tors. NN, two ordinary slide-valves, arranged to form alternate communications between the pipes IX 
and mm, and the exhaust chambers, and P, on the principle of the valves of ordinary high-pressure 
%team-engines ; n n, valve-stems working through stuffing-boxes ri n' ; p } pipe communicating between 



the valve chamber ]c' and exhaust chamber P ; &', pipe leading from exhaust chamber ; Q, pipe leadino 
.nto the receiver G, provided with a stop-cock q. R R, fire-places for heating the vessels H and C ; ri 
r r, flues leading from said fire-places, and terminating at r . S, a cylindrical vessel attached to lha 
working piston b, having a spherical bottom corresponding to the expansion vessel C. This vessel, S, 
which is the heat-intercepting vessel, is to be filled with fire-clay at the bottom, and ashes, charcoal, or 
other non-conducting substances towards the top, its object being to prevent any intense or injurious heat 
from reaching the working piston and cylinder. T T, brick-work or other fire-proof material surround- 
ing the fire-places and heaters. Fig. 653 represents a sectional plan of fig. 1. 

Before describing the operation of the improved engine, it will be proper to observe that the piston- 
rod a' only receives and transmits the differential force of the piston 6, viz., the excess of its acting 
force over the reacting force of piston a. This differential force imparted to said piston-rod may be 
communicated to machinery by any of the ordinary means, such as links, connecting-rods and cranks, 
or it may be transmitted directly for such purposes as pumping or blowing. The conical valves K and 
J may be worked by any of the ordinary means, such as eccentrics or cams, provided the means adopt- 
ed be so arranged that the valve K will commence to open the instant that the piston b arrives at the 
full up- stroke, and be again closed the instant the piston arrives at full down-stroke, whilst the valve J 
is made to open at the same moment, and to close shortly before, or at the termination of the up-stroke. 
In like manner, the slide-valve N' is to open and close as the piston b arrives respectively at its up and 
down stroke, similar to the slide-valve of an ordinary high-pressure engine. 

Before starting the engine, fuel is put into the fire-places R R, and ignited, a slow combustion being 
kept up until the heaters and lower parts of the regenerators shall have been brought to a temperature of 
about 500°. By means of a hand-pump, or other simple means, atmospheric air is then forced into the 
receiver G through the pipe Q, until there is an internal pressure of some S or 10 pounds to the square 
inch. The valve J is then opeued, as shown in the figure ; the pressure entering under tho piston b will 
cause the same to move upwards, and the air contained in A will be forced through the valve F into the 
receiver. The slide-valves N N being, by means of the two stems n n, previously so placed that the pas- 
sages 1 1 are open, the air from the receiver will pass through the wires in L into the heater H, and further 
into C, the temperature of the air augmenting, and its volume increasing as it passes through the heated 
wires and heaters. The smaller volume forced from A will, in consequence thereof, suffice to fill the larger 
space in C. Before the piston arrives at the top stroke, the valve J will he closed, and at the termination 
of the stroke the valve K will be opened ; the pressure from below being thus removed, the piston will 
descend and the heated air in C will pass through V p P and m into the regenerator M, and in its passage 
through the numerous small spaces or cells formed between the wires, part with the caloric, gradually 
falling in temperature until it passes off at o', nearly deprived of all its caloric. The commencement of 
the descent of the piston a will cause the valve F to close and the valve E to open, by which a fresh 
charge of atmospheric air is taken into the cylinder A. At the termination of the full down-stroke, the 
valve K is closed and the valve J again opened, and thus a continued reciprocating motion kept up. It 
will be evident that after a certain number of strokes the temperature of the wires or other matter con- 
tained in the regenerators will change ; that of M will become gradually increased, and that of L di- 
minished. The position of the side valves N N should, therefore, be reversed at the termination of 
every fifty strokes of the engine, more or less, which may be effected either by hand, or by a suitable 
connection to the engine. The position being, by either of these means, accordingly reversed to that 
represented in the drawing, the heated air or other medium passing off from C will now pass through 
the partially cooled wires in L, whilst the cola medium from the receiver will pass througa the heated 
wires of M, and on entering H will have attained nearly the desired working temperature. In this manner 
the regenerators will alternately take up and give out caloric, whereby the circulating medium will prin- 
cipally become heated, independently of any combustion, after the engine shall have been once put in 

The relative diameter of the supply and working cylinder will depend on the expansibility of the 
acting medium employed ; thus, in using atmospheric air or other permanent gases, the difference of 
the area of the pistons may be nearly as 2 to 1, whilst in using fluids, such as oils, which dilate but 
slightly, the difference of area should not much exceed one-tenth. In employing any other medium 
than atmospheric air, it becomes indispensable to connect the outlet pipe o' and the valve-box e of th» 


outlet valve E, as indicated by dotted lines in the drawing, these dotted lines representing the requisite 
connecting-pipe. The escaping air or fluid at o will, when such a connecting-pipe has been applied, 
furnish the supply cylinder independently of other external communication, and the acting medium will 
perform a continuous circuit through the machine under this arrangement; the operation being in other 
respects as before described. The working cylinder may he placed horizontally or otherwise, and it 
may be made double acting ; a heat-intercepting vessel maybe applied at each end of the working pis- 
ton, as also an expansion heater at each end of the working cylinder. 

Stirling's Air Engine. Mr. Robert Stirling, a Presbyterian clergyman in Scotland, and an amateur 
in mechanical matters, made an engine the subject of a patent dated Oct. 1, 1 840, which was described 
before the Institution of Civil Engineers, in 1846, hy his brother, John Stirling. "We present the de- 
scription by Mr. S., as it appeared in the English mechanical magazines at the time. It "will be seen 
that the Ericsson engine is but a slight advance on the engine of Stirling, the principal features being 
substantially the same in each : Stirling used the same air, as well as the same heat, over and over, 
while Ericsson takes fresh air every stroke. By the latter arrangement, cold air is obtained for the 
pump without taking trouble to cool the air of the exhaust, for that purpose, but it involves the neces- 
sity of continually compressing a fresh quantity, a loss which can be but imperfectly compensated for 
by allowing the air to act expansively. Whether the gain or loss is greater in tills arrangement has 
not yet been satisfactorily shown, either in theory or practice. 

The principle upon which the movements of this air-engine depend, is the well-kucwn one in pneu- 
matics, that air has its bulk or pressure increased when its temperature is raised, and diminished when 
its temperature is lowered. 

Two strong air-tight vessels are connected with the opposite ends of a cylinder, in which a piston 
works in the usual manner. About four-fifths of the interior space in these vessels is occupied by two 
similar air-tight vessels or plungers, which are suspended to the opposite extremities of a beam, and ca- 
pable of being alternately moved up and down to the extent of the remaining fifth. By the motion of 
these interior vessels, which are filled with non-conducting substances, the air to be operated upon is 
moved from one end of the exterior vessels to the other, aud as one end is kept at a high temperature, 
and the other as cold as possible, when the air is brought to the hot end, it becomes heated and has its 
pressure increased, and when it is brought to the cold end, its heat and pressure are diminished. Now, 
as the interior vessels necessarily move in opposite directions, it follows, that the pressure of the in- 
closed air in the one vessel is increased, while that of the other is diminished. A difference of pressure 
is thus produced upon the opposite sides of the piston, which is thereby made to move from the one end 
of the cylinder to the other, and by continually reversing the motion of the suspended bodies or plung- 
ers, the greater pressure is successively thrown upon a different side, and a reciprocating motion of the 
piston is kept up. The piston is connected with a fly-wheel in any of the usual modes, and the plung- 
ers, hy whose motion the air is heated and cooled, are moved in the same manner, and nearly at the 
same relative time with the valves of a steam engine. 

The power is greatly increased and made more economical by using somewhat, highly-compressed air, 
which is at first introduced, and is afterwards maintained, by the continual action of an air-pump. The 
pump is employed in filling a separate magazine with compressed air, from which the engine can be at 
once charged to the working pressure. 

If all the heat, however, which is necessary to raise the air to the required temperature, were to be 
thrown away or lost every time that the air is cooled, the power produced by its expansion and contraction 
would be much more expensive than that which is gained by the use of steam. In order, therefore, to 
understand how the work of a good steam-engine has been done, with about one-third of the fuel con- 
sumed by it, it is necessary to point out the method by which the greater part of the heat is preserved, 
and is used repeatedly, in expanding the air, before it is finally wasted or lost. 

For this purpose, when it is necessary to cool the air, after it has been brought to its greatest heat, 
it is not at once brought into contact with the coldest part of the vessels. This would indeed effectually 
cool it, but the heat when thus extracted would be entirely lost, because it could never again be taken 
up by a body warmer than itself. Instead of this, therefore, the air is made to pass from the hot to the 
cold end of the air-vessel through a multitude of narrow passages, whose temperature is at first nearly 
as great as that of the hot air, but gradually declines till it becomes nearly as low as the coldest part 
of the air-vessel. Now, as every body by contact will give out heat to one that is colder than itself, the 
air, when it enters the narrow passages, must give out a portion of its heat, even to the hottest part of 
these passages, and must continue in its progress to give ont more and more, as the temperature of the 
passages is diminished, till at last when it is ready to escape into the cold part of the vessel, there is 
only a small portion of the heat to be extracted, in order to bring it to the lowest temperature required. 
By far the greater part of the heat, therefore, has been left behind, in the metal which forms the pas- 
sages, and which is so contrived and arranged, as to retain that heat until it is again required for heating 
the air. It must be evident also, from the manner in which the heat has been distributed, or spread 
out, over the whole length of those passages, that it is capable of being again employed in heating and 
expanding the air ; for when the cold air is again made to enter the passages for the purpose of being 
heated, it immediately comes into contact with matter that is hotter than itself, and consequently be- 
gins to acquire heat, even at its first entrance ; and as it is successively applied to surfaces of a greater 
temperature, it continues to receive more and more heat, so that when it comes at last to the hot end 
of the vessel, it requires but a small addition to its temperature to give it the elasticity which is neces- 
sary to move the pistou. Thus, instead of being obliged to supply, at every stroke of the engine, as 
much heat as would be sufficient to raise the air from its lowest to its highest temperature, it is neces- 
sary to furnish only as much as will heat it the same number of degrees, by which the hottest part of 
Jie air-vessel exceeds the hottest part of the intermediate passages. 

This arrangement or contrivance for the heating and cooling of air and other fluids, which may h% 


termed the economical process, forms the foundation of all the success which has been attained in pro- 
ducing power, with a small expenditure of fuel. 

This principle was devised and acted upon by Mr. R. Stirling nearly thirty years ago, hut until the 
present time it could not be said to have been beneficially applied to the production of power. The sev- 
eral means by which the principle is at last rendered effective, consist, chiefly, in the employment of 
various means for keeping the piston-rods air-tight, and enabling the pressure of the air to be raised 
to such an extent as to bring the engine into a small compass, and in the introduction of an effective 
refrigerating apparatus for extracting the waste heat and bringing the air to a lower temperature than 
could otherwise have been attained. 

The greatest difficulty which was encountered, consisted in the proper application of the heat to the 
outside of the air-vessels. "When applied directly by radiation from the fire to the spherical bottom of 
the vessels, it necessarily heated one part too much ar.d another part too little, and the overheated part 
was not only liable to rapid oxidation, but by its expansion the other parts were strained and cracked. 
The heat is now applied chiefly by means of the hot-air which passes through the furnace ; and it is 
found that, instead of requiring more fuel to keep up the heat, by this method it is accomplished with a 
considerable less quantity. It is found also that when the flues for distributing the heat over the sur- 
face are properly constructed, the air-vessels are very equally heated, and neither show a hurtful ten- 
dency to oxidation, nor to that unequal expansion by which the air-vessels might be destroyed. 

The first engine of this kind which, after various modifications, was efficiently constructed and heat- 
ed, had a cylinder of 12 inches in diameter, with a length of stroke of 2 feet, and made 40 strokes or 
revolutions in a minute. This engine moved all the machinery at the Dundee Foundry Company's 
works for eight or ten months, and was previously ascertained to be capable of raising 700,000 lbs. one 
foot in a minute. Finding this power to be too small for their works, the Dundee Foundry Company 
erected their present engine, with a cylinder of 16 inches in diameter, a stroke of 4 feet, and making 28 
strokes in a minute. This engine has now been in continual operation for upwards of two years, and 
has not only performed the work of the foundry in the most satisfactory manner, but has been tested 
(by a friction brake on a third mover) to the extent of lifting nearly 1,500,000 lbs. It was found diffi- 
cult to keep this load steadily applied for any length of time, owing to the strap becoming heated ; but 
the engine has been worked for a whole day with a measured burden of 1,250,000 lbs., besides driving 
three extensive lines of shafting 370 feet in length ; and this work is performed with an expenditure of 
1000 lbs. of Scotch Chew coals, including the quantity necessary to raise the heat in the morning, and 
to maintain it during the two hours for meals, when the work was usually stopped. The coals used in 
this case were of inferior quality, and at least one-fourth less capable of producing heat than ordinary 
English coals. Taking this into account, and deducting 150 lbs., the quantity which was ascertained 
to be necessary for raising the heat in the morning, leaves a consumption of 600 lbs. in 12 hours. 
But little has yet been done in improving the furnaces, the principal attention having hitherto been de- 
voted to ascertain the best method of heating the air-vessels, without regard to the economy of fuel. 
This result, although not so favorable as might be expected, is given to show the early capabilities of 
the engine. This engine requires only about a cubic inch of oil to keep the piston and the rod in order 
for two days, and in consequence of this, the friction of the cylinder and piston is decidedly less than it 
is in a steam-engine. In like manner the valves of the air-pump and safety-valves being free from 
moisture, do not show any tendency to get out of order. The leather collars are also very durable, 
that of the piston-rod usually lasting about three months, and the others six or nine months ; and upon 
the whole, the working of the machine, besides the saving of fuel, is altogether more economical and 
less troublesome than that of a steam-engine. 

It was perceived from the beginning, that in order to render the heating and cooling of the air com- 
plete and economical, it would be necessary to make the passages through which it is conveyed from 
one end of the air-vessels to the other, as narrow as possible. This is rendered necessary by the very 
defective conducting power of air, and the consequent difficulty of heating and cooling it. But on the 
other hand, the contraction of the passages, in which the air is heated and cooled, greatly increases 
the force which is necessary to pass it through them ; so that, if they were made extremely narrow, 
the whole power of the engine might be consumed in transferring the air. 

Mr. Stirling exhibited the model of the engine, and explained that the object was to raise the tem- 
perature of the air iu the air-vessel, to such an extent as to obtain a difference of 500° between the 
heated and the cooled states. The air when heated might be taken at 650°, and after it had passed 
through the capillary passages, and the refrigerator, its temperature was 150°. The working pressure 
varied during each stroke from 160 lbs. to 240 lbs. per square inch. 

CAM. If the axle of a wheel be situated in any other point than its centre, the wheel thus rendered 
eccentric, may produce by its revolution an alternate motion in any part exposed to its action. Circles, 
hearts, ellipses, parts of circles, and projecting parts of various forms, are made to produce alternate mo- 
tion, by continually altering the distance of some movable part of the machine from the axis about 
which they revolve. Such projecting parts are called cams. See Eccentrics. 

CAMBER. The convexity of a beam, frame or girder. 

CAMERA OBSCURA. A converging object-glass adjusted to the shutter of a dark room, will con- 
centrate the rays which come from external objects ; and if these objects are very distant, compared with 
the focal distance of the glass, and situated nearly in the direction of its axis, it will give distinct images 
which may he received upon a white screen. These images are inverted; but in order to render them 
erect, it is sufficient to bring to the object-glass, instead of the direct light of the object, that of the image, 
already reflected and inverted by a metallic mirror. This apparatus is called a camwa obscura. A plate 
of ground glass may he substituted for the screen, and for the room, a box fitted by means of a curtain 
to receive the head. It can then be transported with ease, for the purpose of landscape sketching. 

Camera Lucida. If a quadrangular prism be cut in such a manner that the rays coming from neigh- 



boring objects, and falling nearly perpendicularly upon its first surface, shall twice experience total reflec- 
tion at its interior faces, and then, emerging perpendicularly through its last surface, arrive at the eye, an 
erect and horizontal image of the object, Mill appear to come through the prism. But if the pupil of the 
eye be so placed, that the rays thus reflected shall occupy only half of it, the other half jutting a little 
oyer the edge of the prism so as to admit the rays coming directly from a piece of pasteboard placed 
below ; it is evident, that in this manner the spectator will see at once, with the same eye, the imago 
and the screen upon which it appears to be thrown. If then he wishes to sketch the outlines with a fine 
pointed pencil, he will see at the same time the point of this pencil and the image, aud there will be 
nothing to prevent bis delineating it. This ingenious instrument was invented by Dr. Wollaston, and 
is frequently used by draughtsmen m copying details from Topographical Drawings. 

CAMPHOR WOOD. See Woods, varieties of. 

CAMWOODS. See Woods, varieties of. 

CANALS. Canals are open channels of water for the purposes of navigation, water supply fty cities 
and manufactories, for drainage, for irrigation, &c. The form and size of the canal will denend upon 
the purposes to which it is to be applied. Kor navigation, on the size of the boats and the amount of 
traffic. For water supply, drainage, &c, on the amount of water to be supplied or discharged. 

The following Table is from Wm. J. Mo Alpine's Report to the N. Y. Legislature, in 1853. 




Cost per 
in lie. 

c £ 




- - 



Cayuga and Seneca, . . 

Central Division, . . . 
Western do .... 
.Susquehanna Division, . 
North Branch, .... 
North Branch Esten., . 

Delaware Division, . . 
Beaver do . . . 


Delaware and Hudson, . 

do enlarged, 

Del. &Earitan & feeder, 
Morris and Essex, . . 


New Yor! 

=,. • 
















60 1 






































29 locks I 
22 planes J 















so' ' 
ioo' ' 

50 i 
140 f 

150 ' 




Penn., public, . 
do . . . 
do . . . 
do . . . 
do . . . 
do , . . 
do . . . 
do . . . 


Penn., private., 
do ... 

Penn., .... 

N. Y. and Penn., 

do . . . 

New Jersey, . 
do . . . 











'26,'647 ' 










j $2,500,000 
| 6,500,000 








(Chesapeake and Del., . 

Chesapeake and Ohio, . 

Del. and Md., . 
do . . . 





$l'2,750,ili hi 


Ohio and Erie, . . . 

Sandy and Beaver, . . 







do ... . 
do .... 
do .... 




James R. and Kanawha, 

Wabash and Erie. . . 
do .... 

111. and Michigan, . . 

St. Lawrence, .... 
Beanharnois, .... 

Virginia, . . . 

Indiana, . . . 
do . . . 

Illinois, . . . 

Canada, . . . 
do . . . 
do . . . 
do . . . 
do . . . 
do . . . 



















CANALS. 23£ 

For the enlargement of the Erie canal, the following dimensions have heen adopted : — "Width at wa- 
ter-line, 70 feet. Width at hottom, 28 feet. Depth of water, 7 feet. Width of tow-path, 14 feet. 

The Caledonian canal in Scotland is remarkable for its size, which will admit of the passage of 
frigates of the second class. Its principal dimensions are as follows : — Width at water-line, 1 00 feet. 
At bottom, 50 feet. Depth of water, 20 feet. Length of locks between mitresills, 180 feet. Width of 
chamber at top, 40 feet. Lift of lock, 8 feet. 

Crossection. In canals of this country the interior slopes are generally uniform, from 1^ to H hori 
lontal to 1 perpendicular, the slopes being paved or rubbled near the top, to prevent the wash. The 
tow-paths are about two feet above the level of the water, and from 6 to 12 feet wide. The path should 
elope outwards from the canal so that the surface water and earth may not be earned into the channel. 
With regard to the supply of water necessary for a canal, or for a level of canal, it embraces the quantity 
required for the service of the navigation, that is, the number of times the chambers of the locks will re- 
quire to be used in the passage of boats, and the losses arising from evaporation, from leakage through 
the soil and through the lock gates, the necessary first fillings of the levels and the chance of accidents 
or breaches, and the emptying of the levels for repairs. In estimating the quantity expended for the 
service of navigation the problem is simple, knowing the capacity, form and number of locks, the size of 
boats and the contemplated amount of traffic. With regard to the other losses it must be a great deal a 
matter of conjecture. From experiments made by Mr. J. B. Jervis on the Erie canal, the total loss from 
evaporation, nitration, and leakage through the gates, is about 100 cubic feet per minute for each mile. 
Having determined the amount of water required, the source of the supply must be guaged, and if the 
minimum flow of the stream be not sufficient, reservoirs must be constructed to equalize the supply. For 
the forms and dimension of locks, see " Locks of Canals." 

On the cost of transportation on canals, we again extract from the able Report of Mr. Mc Alpine. 

The cost of transportation of coal in 1848 on the Chesapeake and Ohio canal from Cumberland to 
Georgetown, a distance of 184.4 miles, was §78.06, or 4| mills per ton per mile, including the interest 
on the cost of the boats and fixtures, annual repairs and depreciation on the same, cost of towing, wages 
of men, cost of loading and unloading. 

The cost of transportation of coal on the Schuylkill canal is §44.54 for 10S miles, or 4j* mills per ton 
per mile ; the cost on the Delaware and Hudson canal is about the same. 

The cost of all expenses of running, towing, and decrease of value of horses, office and personal ex- 
penses, and part cost of loading and unloading on the Erie canal in 1852, was 2, 9 mills per ton per 
mile. Mr. Seymour, the late State engineer, estimated the whole cost at 3 J mills per ton per mile. The 
charges for transportation on the Erie canal in 1851 and 1852 (except late in the season) have averaged 
$2.50 per ton for down, and §2.35 per ton for up freight (exclusive of the charge for State tolls), being 
at the rate of 6.9 and 6.5 mills per ton per mile. 

The charges for transportation of coal on the Schuylkill canal in 1S52, was §0.65 for 108 miles, or 6 
mills per ton per mile ; and on the Delaware and Hudson canal, about 5^ mills per ton per mile. On 
the latter canal they have ascertained that the cost of transportation has been reduced more than forty 
per cent, by enlarging the canal from a capacity for boats of 50 tons fo that of 115 tons. 

In 1848, thi Delaware and Hudson Canal Company determined to enlarge the dimensions of their 
canal for the purpose of accommodating the increased amount of trade, and to cheapen the cost of 
transportation. This has been accomplished at an expense of about 2} millions of dollars. 

The engineer of that work, R. F. Lord, Esq., prepared very careful estimates of the saving in the cost 
of transportation which the enlargement would effect, as follows: "The charge for freight on the old 
canal which was competent for boats of 50 tons, was §1 per ton for 108 miles, or nearly one cent pel 
ton per mile. The estimated charge for freighting with the canal enlarged for boats of the following 
tonnages, was : 

"For 100 tons, 65 cents, equal to 5," mills per ton per mile. 
116 tons, 58 cents, equal to 5, 4 mills per ton per mile. 
136 tons, 50 cents, equal to 4 , u n mills per ton per mile. 

The company determined to enlarge the canal to the last mentioned capacity, which has been done, and 
boats now carry from 115 to 141 tons, at a saving in the cost of transportation equal to that estimated. 

Canals for the supply of water to cities or to manufactories, are generally walled at the sides, and 
are deeper in proportion to their width than those used for the purposes of navigation. The area of their sec- 
tion is to be proportioned to the quantity to be supplied. The mean velocity is usually from 1 to 2 feet 
per second. The greater the velocity the more the inclination of the surface and the consequent loss of 
head and fall. It becomes then a matter of calculation, how much may be saved by the first invest- 
ment by the construction of a canal of small area, and a consequent continual loss of available power. 
For the rules for calculating the flow of water in canals, see Hydraulics. 

The velocity of the water in a water-course should be neither too slow, for then the course chokes with 
weeds, nor too fast, for then the bed of the channel may be disturbed, and besides, too much fall must 
not be lost in the inclination of the course. 

A velocity of 7 to 8 inches per second is necessary to prevent deposit of slime and growth of weeds, and 
1J feet per second is necessary to prevent deposit of sand. The maximum velocity of water in canals 
depends on the nature of the channels' bed. 

On a slimy bed the velocity should not exceed \ ft, 
" clay " "...+" 

" sandy " "... 1 " 

" gravelly " "... 2 " 

On a shingle bed the velocity should not exceed 4 ft 
" conglomerate " "... 5 " 

" hard stone " "... 10 " 

This applies to the mean velocity. 

The water-courses for water-wheels and general uses of the Freyberg mining district have inclinations 
varying from 15 inches to 30 inches per mile. The New River which supplies a great part of London, 
das an inclination of -ppnr P er m ^ e - 


CAN ART- WOOD. See Woods, varieties of. 

CANGICA WOOD. See Woods, varieties of. 

CANDLES, Wax. Next to tallow, the substance most employed in. the manufacture of candles is 
wax. Wax candles are made either by the hand or with a ladle. In the former case, the wax being 
kept soft in hot water, is applied bit by bit to the wick, which is hung from a hook in the wall ; in the 
latter, the wicks are hung round an iron circle, placed immediately over a large copper-tinned basin 
full of melted wax, which is poured upon their tops, one after another, by means of a large ladle. 
When the candles have, by either process, acquired the proper size, they are taken from the hooks, 
and rolled upon a table, usually of walnut-tree, with a long square instrument of box, smooth at 
the bottom. 

CANDLES, Stearic — Manufacture of. Among the tallows which are best adapted for the prepara- 
tion of stearic candles, are those of beef and mutton. All other fatty matter is poor in solid acid, 
or of too considerable a price. It is, then, the quantity of acid, stearic or margaric, which is found in a 
given weight of beef or mutton, and the facility in working the same, which ought to determine in 
giving preference to this or that quality of tallow. The mutton tallow contains the greater quantity of 
solid acid, and is the more easily worked. That of beef is, generally speaking, to be procured a little 

The manufacturers of stearic candles, to free themselves from the inconvenience of melting, are gen- 
erally in the habit of buying from the butchers fat already melted. This method is far from being 
the best, as it is almost impossible to judge the purity of the tallow when it has been melted, and at 
the same time gives an opening for imposition to a considerable extent. Thus it would be most im- 
portant to the manufacturer to purchase the tallow in lumps, in such manner as it is taken from the 
animaL covered with its membranes, and bound in its cellular tissue, and to melt it himself. 

This operation of melting is performed in the slaughter-houses of Paris in a very simple manner. 
They have a great copper, from 6'56 feet to 7'21 feet diameter, and from 3'28 feet to 3.93 feet in 
depth, swelling at the bottom as in a stewpan, and widening at the top, so as to be enabled to rest 
upon a circular oven. This is constructed in such manner that the hearth, of a breadth of 1'32 feet, is 
exactly under the copper, from its circumference to its centra The flame and hot air heat at first the 
whole of the bottom surface, and then circulate twice round the cylindrical part of the copper before 
passing up the chimney. They throw the fat in this copper by an inclined plane, which proceeds from 
the upper story, and during the melting they stir it with a long rod. When they have reached a 
proper degree of fusion, which is generally obtained in about four or six hours, according to the nature 
of the fat, they turn it out, first into a large iron-plate reservoir, of the same size as the copper, and 
which is furnished with two cocks, from which it is drawn off into slightly conical vessels, so as to form 
large lumps of a conical shape. 

It is well to place under the copper a large funnel, the same as in a forge, to conduct the gas wlucl 
escapes from the fat during the operation to the chimney. There should be also in the same fac- 
tory a screw-press, for compressing the membranous part, in order that no portion of fat may be 

The different operations in general use for the manufacture of such candles are generally divided as 
follows : 

1st. The formation of soap; the object of which is to combine the acidulated fat with the lime, to 
produce the glycerine, and obtain the stearate, margarate, and oleate of lime. The glycerine dissolves 
itself in the water necessary for this preparation. 

2d. The pulverizing of the lime soaps. 

3d. The decomposition of these same soaps by sulphuric acid diluted with water. 

4th. The cleansing of these stearic, margaric, and oleic acids — first, by water slightly acidulated, and 
secondly, by pure water. 

5 th. The moulding and crystallization of the now obtained acid fats. 

6th. The melting of the crystalline masses into small layers instead of large rolls. 

7 th. The cold-pressure of the acids thus formed into layers. 

8th. The hot-pressure of these layers now reduced. 

9th. The purification of the soUd acids by water slightly acidulated at first, and secondly by pure 

10th. The melting and moulding of the solid acids into moulds ; then the clipping of the candles. 

11th. The bleaching of the candles. 

12th. The polishing, packing, &c, for removal. 

Description of the Machinery. — Fig. 652 represents the general plan of a manufactory, indicating the 
utensils which are employed. 

Fig. 653 is a sectional view of this manufactory, vertically and longitudinally; and the figures 654, 
655, 656, and 657, represent in elevation, or sectionally, the details of the principal utensils, and the 
means of communicating the movement, 

The Formation of Soap. — This operation is performed in a large vat, generally constructed of wood, 
slightly conical in form, and provi led with several frets all the way up. The bottom and the lid are 
of wood, and its capacity is sufficiently great to contain, easily, more than 70-58 cubic feet. They gen- 
erally place about HOOlbs. of tallow, with a proportion of water rather more than enough to easily 
dissolve the same, and which would be about 200 gallons. This is heated by steam from a leaden 
pipe g, winding in a serpentine manner, and placed at the bottom of this trough. This pipe is per- 
forated with a number of small holes, across which the steam passes as it proceeds from the coppers 
A or A', with which it is in communication. When this is melted, they add, by degrees, 165 lbs. of 
lime well mixed; and they allow this preparation time to mingle, taking, at the same time, great care 
to stir it by means of an agitator p, composed of many branches united by a cross-piece, and having a 


kind of knife fixed at each of the four arms. This contrivance is mounted upon a vertical beam o. 
to which is given a rotary movement by the wheel n fixed to the upper part of the beam. 

This wheel is acted upon by a pinion n' adjusted upon the horizontal beam, which commimicates with 
the prime mover by the two pair of cog-wheels I 1' and J/, mounted on one part upon the vertical beam 
k; and on the other part upon the horizontal beam F, as seen in Figs. 652 and 653. An energetic stir- 
ring is most important, because it more fully completes the formation of soap, and economizes, conse 
miently, the sulphuric acid. 

Generally, in the greater part of the manufactories, says lions. Dumas, they use, perhaps, 33 !bs., 
and sometimes more, of sulphuric acid, to the 220 lbs. of tallow, while they ought only to use from 19 
to 22 lbs. to 220 lbs. of tallow. It is often, then, a tlnrd too much, and an experienced manufacturer 
would do well to pay attention to this. 

They had proposed to give the movement to this agitator by means of a cord, but they found they 
were obliged to give up this, as they could not obtain a regular movement — during one part of the 
operation the matter, being very compact, would present a great resistance, and the rope would give. 

The time for the formation of soap is generally from 6 to 8 hours. At the end of this period they 
draw off, by means of a tap q' placed in the bottom of the trough, the liquid part which has absorbed 
the glycerine, and they take from the trough all the solid which remains there, which is now a forma- 
tion of stearate, margarate, and oleate of lime, in the form of a very hard soap ; this they throw upon 
the floor, upon which rests the trough J. 

Pulverizing. — To pulverize the soap, they use, in many manufactories, a roller of cast-iron K, which 
they pass to and fro in an alternate movement, and generally by manual labor. Mons. Dumas proposes 
to have the soap pass between two cylinders moistened by a stream of cold water, which should bathe 
it ; a precaution most indispensable, because the soap, heated by the pressure, would soften, and render 
itself more often in cakes than in powder. 

Troughs for Decomposition. — The two troughs J 1 and J", into which is conveyed the solid matter after 
it has been broken, are designed for the decomposition of these matters by the action of sulphuric acid 
much diluted with water. Like the former, in shape they are slightly conical, and nearly of the same 
dimensions, heated by steam by a serpentine pipe q'. They ought, also, as with the former troughs 
for the formation of soap, to be cased with lead, so as to be protected from the action of the sulphuric 
acid. It would be quite as well to fit up both with a mechanical agitator, though in many manufac- 
tories they are not so. These troughs are generally on a lower floor, under the trough for the forma- 
tion of soap, so that they can easily dispose of the matter. 

The quantity of sulphuric acid necessary for the decomposition of these lime soaps can be easily de- 
termined. For 1100 lbs. of tallow, according to Mons. Dumas, they would use 165 lbs. of lime; or for 
220 lbs. of lime the equivalent in sulphuric acid is equal to 367 lbs., at 66° centigrade. Consequently, 
for 165 lbs. of lime will be necessary 275 lbs. of this acid. In practice they add from 10 to 15 per 
cent, to this quantity, and the acid being, we suppose, at 66°, they dilute it by twenty times its quan- 
tity of water. At the end of about three hours the decomposition of these soaps is effected. They 
then displace the mass. The fat acid comes to the surface, and the sulphate of lime is precipitated to 
the bottom. 

Cleansing the Acids. — For this purpose they withdraw, by means of a tap <?', which is placed un- 
derneath, and which, like the preceding ones, is cased in lead, and equally heated by steam by a ser- 
pentine pipe placed in the bottom. It is as well to have a second trough L, similar to the preceding 
one, to complete the cleansing, in which they work only with pure water. The passages E, inserted in 
the interior of the roof, serve to establish a communication with the two troughs of decomposition J J', 
and with those of cleansing L L', and to carry the liquid off or into the lower reservoirs. As much as 
possible of sulphuric acid and lime are drawn off into a series of zinc moulds II, which are arranged 
in rows along the entire length of the workshop, in such manner, that in drawing it off into the first 
mould it flows gently into the adjoining moulds, which is easily done by attaching to each brim of thfe 
moulds a gutter, wliich carries off the superfluous matter at its proper height 

These moulds present the form of a rectangular prism from 27 to 39 inches in length, from 6J to 7 
inches in breadth, and about 16J feet only in height. Thus are formed layers of solidified acid, which 
are taken away (after being wrapped in woollen serge) to the vertical hydraulic press N, which is con- 
structed exactly similar to the ordinary presses, of which it is easy to see the construction by reference 
to the